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600 mw generator

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Index...........................................................................................................................................- 0 Part I overhaul manual of turbine generator ..................................................................- 1 Part II generator set protection and automatic devices ............................................- 31 Chapter I verification manual about microcomputer type generator protection devices ......... - 31 Chapter II verification manual of UN5000 excitation system ...................................................... - 47 Chapter III verification manual of generator synchronization device ........................................ - 56 Chapter IV verification manual of fault recorder of generator-transformer unit ..................... - 63 -

Part III inspection manual for instruments ........................................................................68
Chapter I Inspection and technical manual for electrical measuring transducer........................... 68 Chapter II overhaul manual for electrical measurement digital meter ........................................... 73

Part IV electrical equipment overhaul manual for electrostatic precipitator ............80

Part I overhaul manual of turbine generator
1 Overviews and technical specifications for turbine generator and its auxiliary equipments 1.1 Overview This regulation is applicable to India NAGARJUNA 2×600MW coal fired unit QFSN-600-2-22 F three-phase two-polarity synchronous generator , which is directly driven by the turbine. This turbine generator is made by Dongfang Electric. For which “water-hydrogen-hydrogen” cooling method is employed, which means stator coils(including stator leading wire, stator transition leading wire and outlet wire) are cooled by internal water-cooling method; internal hydrogen cooling method for rotor coil; surface hydrogen cooling method used for stator core and end structural component. Air cooling method is adopted for collector ring. Hydrogen inside the base will be driven by axial flow fan which is mounted at the both ends of the rotor and be forced to circulating inside the sealing environment. “unit end voltage transforming static rectifying self-shunt excitation system“ is adopted for excitation. 1.2 TECHNICAL DATA 1.2.1 BASIC SPECIFICATION Type Rated output Maximum continuous output Maximum permissible capacitive Loading at full load Maximum capacitive loading for stability At rated voltage & zero power factor Stator coil copper loss Stator iron loss Excitation loss Short-circuit additional loss Mechanical loss Total loss Rated voltage Rated current Rated power factor Rated frequency Rated speed Number of phases Stator winding connection Number of terminal Insulation class Cooling mode

QFSN-600-2-22 F 600 MW (706 MVA) 640 MW (753 MVA) 208 MVar 300 MVar 1858.8 kW 837.56 kW 1883.0 kW 1232.4 kW 1105.79 kW 6917.6 kW 22 kV 18.525 kA 0.85 lagging 50 Hz 3000 r/min 3 YY 6 F(temp. limited in B class) H2O—H2—H2
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Rated H2 pressure Excitation type Short circuit ratio Efficiency Telephone harmonic factor Guaranteed maximum noise (at 1 m. distance from the Generator outline) 1.3.2. DESIGN DATA(CALCULATED DATA)

0.45 Mpa(g) Static Thyristor Excitation ≥0.5 ≥98.8% ≤1% ≤85 dB

DC resistance of stator winding (per phase) DC resistance of field winding Rated field voltage Rated field current Reactance:
Item Direct-axis synchronous (xd) Quadrature-axis synchronous (Xq) Direct-axis transient (Xd') Quadrature-axis transient (xq') Direct-axis subtransient (Xd") Quadrature-axis subtransient (xq") Negative phase-sequence (x2) Zero phase-sequence (Xo)

0.001 456 Ω(at 15℃) 0.06771 5Ω(at 15℃) 431 V (at 100℃) 4727 A

Saturation 184.11% 184.11% 25.39% 25.39% 18.85% 18.85% 21.1 7% 9.16%

Unsaturation 200.18 % 200.18% 28.85% 28.85% 20.49% 20.49% 23.01% 9.64%

Capacitance of stator winding (per phase) 0.243 µF Inductance of rotor winding 0.521 H Field winding time constant( open circuit) Tdo=8.446 s Transient time constant ( 3 phase short circuit) Td3' =1.0714 s Transient time constant (line-line short circuit) Td2'=l .77673 s Transient time constant (line-neutral) Ta1'=2.04173 s Subtransient time constant (3 phase, line-line & line-neutral ) Td"=0.035 s Armature time constant (aperiodic component, 3 phase, line-line) Ta3=0.25604 s Armature time constant (aperiodic component, line-neutral ) Ta1=0.20761 s Mechanical inertia time constant of rotor 1.475 s Quadrature-axis transient open-circuit time constant T'qo=0.938 s Quadrature-axis transient short-circuit time constant T'q=0.118 s Quadrature-axis subtransient open-circuit time constant T"qo=0.047 s Quad rature-axis subtransient short-circuit ti me constant T"q =0.035 s

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Sudden short circuit current (p.u., base value is 1 8525A)
Item Initial subtransient component (effective) Initial transient component effective) nitial aperiodic component Initial short-circuit current (effective) Initial short-circuit current amplitude) Sustained short-circuit current 3 phase 6.07 4.635 7.877 9.944 16.461 1.519 line-line 4.952 4.378 6.426 8.112 13.429 2.38 line-neutral 6.98 6.337 9.058 11.435 18.929 3.959

The maximum electromagnetic torque at line-line short circuit 1477 t.m (6.438MN) Inertia moment GD2 39.0 t.m2 Unstable speed of bearing >8000 r/min Critical speed of generator rotor 1st 982 r/min 2nd 2671 r/min. Thermal expansion of rotor in length at rated operation condition 8.7 mm Rated lightning impulse withstand voltage(kV peak) 4Un+5 as per IEC 60034-15 Rated power frequency withstand voltage(kV r.m.s) 2Un+1 as per IEC 60034-15

1.2.3. LIMIT OF TEMPERATURE AND VIBRATION 1.2.3.1 LIMIT OF TEMPERATURE
Item Stator winding outlet water Stator winding Limit(℃) ≤90 ≤120 Remarks Embedded thermocouple Embedded RTD

Stator winding temp. difference (Max.-Av.) Field winding Stator core Structure part of stator end

≤12 ≤115 ≤120 ≤120 Resistance Embedded thermocouple Embedded thermocouple Thermometer Embedded thermocouple Embedded RTD

Collector ring Bearing Bearing outlet oil & sealing outlet oil

≤120 ≤90 ≤70

1.2.3.2 VIBRATION ( at rated speed:3000 r/min) Bearing pedestal ≤0.025 mm
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Shaft 1.2.4 COOLANT 1.2.4.1 HYDROGEN Rated pressure Maximum pressure Purity Dew point Cold hydrogen temperature Hot hydrogen temperature Hydrogen leakage

≤0.075 mm

0.45 Mpa(g) 0.5 MPa ≥98% -25 ℃~-5 ℃ 448 ℃ ≤68 ℃ ≤1 4 Nm3/day

1.2.4.2 STATOR WINDING DEIONIZED WATER Inlet temperature 40~50 ℃ Water quantity Inlet pressure Conductivity (25 ℃) PH value H ard ness NH3 1.2.4.3 HYDROGEN COOLER WATER Number of coolers Inlet water temperature Outlet water temperature Water quantity Inlet pressure Water pressure drop 1.2.4.4 BEARING LUBRICATING OIL Quantity of generator bearing Quantity of steady bearing Inlet oil pressure Inlet oil temperature Outlet oil temperature 1.2.4.5 GLAND SEAL OIL Inlet oil temperature Outlet oil temperature Quantity Seal oil pressure higher Than hydrogen pressure 5.6 HYDROGEN VOLUME Hydrogen volume in generator 35~45 ℃ ≤70 ℃ 2 x 90 L min 0.056±0.02 Mpa 96 t/h 0.1--0.35 Mpa 0.5--1.5 µs/cm 7~ 9 ≤2 µmol / L Trace amount 4 20--38℃ ≤48 ℃ 4* 115 t/h 0.2--0.3 M Pa 0.032 Mpa

2* 533.5 L/min 25 L / min 0.05--0.10 MPa 35~45℃ ≤70 ℃

86 m3

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1.2.5 DIMENSIONS AND WEIGHTS OF MAIN COMPONENTS Outer diameter of stator core 2625 mm Inner diameter of stator core 1312 mm Length of stator core 6731 mm Gas gap (one side) 94 mm Number of stator slots 42 Number of stator winding branches 2 Weight of stator (The maximum lift, 266 t including trunnious, loots etc.) Transporting weight of stator 258 t (excluding trunnious, loots etc.) Transporting dimensions of stator (L*W*H) 9200*3820* 3850 mm 2 Overhaul cycle and item for generator 2.1 Overhaul cycle of generator 2.1.1 During the whole service life of the generator,major or minor overhaul shall be scheduled periodically. 2.1.2 The first major overhaul for generator set shall be performed in the next year after being put into service, and after that overhauls shall be conducted every three or four years。 2.1.3 Minor overhaul for generator set can be arranged in the interval between two adjacent major overhauls if necessary.(usually, once for every year) 2.1.4 Emergency overhaul after fault happening, and those upgrade and improvement for equipments which can not be coordinated with scheduled major or minor overhaul, shall be arranged in accordance with actual situations. 2.2 Major overhaul items for generator: (form 1) Form 1. Major overhaul items for generator Component Standard items name 1.1 Test prior to generator overhaul(measuring insulation resistance and absorption ratio, and DC leakage current; conducting AC or DC voltage withstand test; measuring DC resistance of winding of each phase after being cooled. 1.2 Disassembly of generator, pulling out rotor; 1.3 Cleaning of stator(including stator core ventilation channel, end cover, inner end cover, bearing shell, sealing base, sealing ring, stator base, stator wire outlet base 1 Stator internal, stator wire outlet sleeve and stator winding water loop reverse washing); 1.4 Inspection for stator(including core end, end fingers, stator working tube, stator bar, notch packing piece, winding end, end binding, coil brace, coil circular leading wire, transition leading wire, connection block fixture, stator insulating diversion pipe, wire outlet sleeve, thermometer, resistor thermometer); 1.5 Conducting stator water system hydraulic test and flow test; 1.6 Painting the winding end. 2.1 Insulation test prior to rotor winding overhaul(including rotor winding cold state DC resistance, static AC impedance as well as insulation resistance to ground); 2 Rotor 2.2 Cleaning rotor(including ring collector, rotor ventilating duct and rotor end winding) 2.3 Rotor inspection(including inspection and treatment for rotor surface, connection
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3 Hydrogen cooler system

4 Carbon brush and carbon brush holder 5 Whole test 5.1 Whole air tightness test for generator; for 5.2 Insulation test for stator and rotor after overhaul; generator 5.3 Measuring rotor AC impedance, generator no-load and short-circuit after characteristics after startup reassembly 2.3 Minor items of generator overhaul:(table 2) Table 2. Minor overhaul items for generator Component Normal items name 1.1 Replacement of hydrogen 1.2 Cleaning and inspection, to adjust and replace for brush 1.3 Cleaning and inspection for slip ring surface and vent 1.4 To conduct reverse flush for stator circuit of generator 1 Generator 1.5 Preventive test for generator 1.6 To clean and check pipeline valves of hydrogen system and hydrogen dryer of generator, and replace with silica gel 1.7 To recharge gas for replacement 3 Overhaul technical regulation for turbine generator 3.1 Preparations for generator overhaul 3.1.1 Preparations for overhaul 3.1.1.1 Approved overhaul items shall be arranged and scheduled. Specific quality requirements and standards shall be clarified, and organizing measures and technical measures and safety measures shall be developed. All the technical issues shall be clarified to technicians. 3.1.1.2 To prepare materials and spare parts for overhaul 3.1.1.3 To prepare all the tools and instruments required by overhaul. 3.1.1.4 To arrange overhaul site for various components. 3.1.1.5 To prepare data, drawings and technical measuring record for overhaul. 3.1.1.6 To ensure fire-fighting and safeguard measures of overhaul site 3.1.2 The following conditions shall be met prior to major overhaul
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part between retaining ring and proper, retaining ring, central ring, fan vane, fan stay ring and ring collector, and bolts, pins, balancing screws, conductive screw, balancing block, rotor notch wedge, journal, nylon air-conducting vane under central ring) 2.4 Test for rotor air tightness and ventilation 2.5 Reassembly of generator rotor 2.6 Measurement of air gap of stator and rotor. 3.1 To disassemble water tank, to cleanse cooling pipelines internal wall with nylon brush; 3.2 To sweep and clean copper heat sink with hot water to remove dirt; 3.3 To check all the rubber gasket, and replace those have been damaged or hardened. 3.4 To conduct hydraulic test; 3.5 Cooler shall be purged and dried with compressed air after cleaning to avoid corrosion. 4.1 Inspection for carbon brush of collector ring, and replacement for carbon brush; 4.2 Purging, inspection, emplacement and adjustment for brush holder.

3.1.2.1 Technical measures about major and special project construction have been approved. 3.1.2.2 Overhaul schedule, technical measures, safety measures and quality standards have been submitted to overhaul technician. 3.1.2.3 Labors, main materials and spare parts have been available. 3.1.2.4 Special tools, construction tools, safety appliances and equipments for test have been verified through tests. 3.1.2.5 Major overhaul items, technology and technical standards have been posted at working site. Various technical data forms and recording book shall be ready and designated to particular personal respectively. 3.1.2.6 Work-order cars shall be prepared in accordance with manual of safety work. 3.2 Disassembly of equipments 3.2.1 Notes prior to disassembly 3.2.1.1 Before commencement, Directors shall examine whether on-site safety measures are satisfied with relevant requirements in accordance with safety working requirement. 3.2.1.2 Duty director shall explain work project, schedule, standards, safety issues and etc clearly prior to commencement. 3.2.1.3 Disassembly and entrance into generator only be allowed when content of hydrogen and carbon dioxide have been identified being controlled in required level. 3.2.1.4 Tools for on-site use must bee registered and managed by particular person. Tools kits must be placed at designated location. 3.2.1.5 During disassembly, those equipments shall be treated carefully. All the dismantled parts shall be labeled prior ot disassembly and put into designated location or parts box. Particular person shall be responsible for preserving those parts. 3.2.1.6 All the measured data shall be recorded into special-purpose log book clearly and accurately. 3.2.1.7 During bridge lifting, particular person shall be designated to command, and rotor axial diameter, fan, retaining ring, slip ring, ventilating jack and so on shall be free of load. Slip ring surface shall be covered with rubber or insulating paper tightly, bend radius of cables shall be treated carefully to avoid mechanical damage. 3.2.1.8 Bigger dismantled components shall be placed firmly. Anti-rolling and collapsing measures shall be taken. 3.2.1.9 Working hours, materials, and schedule shall be recorded timely. 3.2.1.10 Smoking and tools that can produce sparks are strictly forbidden at working site. If electrical drill and flat spade and such as need to be use, construction place shall be purged with compressed air. Tools like Drill bit and flat spade must be wet with oil. 3.2.1.11 Vent of rotor shall be protected against dirt. 3.2.2 Work prior to disassembly 3.2.2.1 Replacement after shutdown Requirements: to check whether volume of carbon dioxide is adequate prior to replacement,(replacement during rotor is inactive shall not be less than 25 bottles). Check whether thread of bottle mouth is intact and good. Person of chemical assay shall be contacted. Internal pressure during placement can be kept at 0.6-0.8Kg,or be identified according to requirement of operator, oil level in sealing oil tank must be checked to avoid oil entering. Hydrogen discharge shall be stopped when carbon dioxide concentration has exceeded 95%, and dry compressed air shall be filled continuously. Operation order can be issued after internal pressure has been kept at 0.1Mpa for 2 hours, and sealing oil system can be shut down. 3.2.2.2 Examination for water drainage
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If major overhaul is carried out in winter, cooling water in generator stator and hydrogen cooler shall be exhausted to avoid being frozen; if major overhaul is performed in summer, water shall be exhausted and purged completely, otherwise, water shall be switched to circulation mode to avoid formation of sediment. 3.2.3 Disassembly of generator 3.2.3.1 To dismantle generator leading wire, and conduct preventive electrical test prior to disassembly of generator. Test project 1、Insulation test for stator three-phase winding: to measure three-phase stator coil insulation to ground and phase-to-phase resistance with 2500 megohm-meter. Technology and quality standards Comparing with factor set value, the difference shall not be significant, absorption ratio ≥1.6, polarization index≥2.0, three-phase unbalancing coefficient shall be less than 2. Rotor coil DC leakage test and DC voltage withstanding test: testing voltage shall be 2.5 times rated voltage, the difference of leaking current of each phase shall not exceed 100% of the minimum value; for those case under 20μA, the difference between each phase shall not be significant. The leaking current shall not be increased as time going. Stator coil AC voltage withstanding test: the insulation resistance of stator three-phase winding to ground and phase-to-phase shall ≥3MΩ,AC testing voltage shall be 1.5Un, which shall be conducted within one minute .

2 、 Test of stator coil DC leakage and DC voltage withstanding test: testing voltage shall be defined as 5 increasing stages in 0.5Un, for every stage, leaking current value shall be read after 1min, and voltage shall be increased to 2.5 times rated voltage

3、AC voltage withstanding test for stator coil: after verification of DC test, water shall be filled with water(water conductivity shall not exceed 1.5μσ/cm, and ph value shall vary within 8-9),. 1.5Un AC Testing voltage shall be applied to three-phase stator coil, which shall be conducted within one minute.

0.5MΩbearing insulation resistance of turbine generator set shall not be less than 0.5MΩ. 4. Insulation measurement for various part of bearing: insulation resistance of sealing pad of generator steam excitation bearing shell, and central ring, left and right bearing base, outer oil baffle cover, bearing shell pad, high pressure oil inlet pipe shall be measured with 500V megger. 3.2.3.2 To dismantle leading wire of generator slip ring(labeled before dismantling), then take out carbon bush of slip ring, dismantle and lift away brush holder on slip ring. Those dismantled brush holder and brush shall be kept properly to avoid damage and missing. 3.2.3.3 To contact turbine technician to dismantle various oil pipelines and upper half outer end cover and bearing. Sealing pad must be uninstalled.
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3.2.3.4 To dismantle upper end cover at both side of generator, to measure clearance between air-conducting cover and fan vane as original data for reassembly purpose. 3.2.3.2 To dismantle upper and lower end covers at both side of turbine excitation system, to dismantle upper and lower air-conducting cover, those parts shall be labeled before uninstallation. To measure air clearance between generator stator and rotor, the difference of maximum and minimum of four radial air clearance shall not exceed 10% of average, and relevant record shall be made. Hydrogen cooler 3.2.4 Extraction of generator rotor 3.2.4.1 After coupling screws of generator and turbine have been unscrewed, special supporting tools for rotor lifting shall be mounted, and rotor can be lifted out with coordination of turbine staff, to take out bearing shell from turbine and oil baffle cover. Relative position of rotor steam end to turbine low-pressure cylinder shall be marked prior ot disconnection of coupling. 3.2.4.2 To mount tools for lifting big cover, to lift lower end cover with chain hoist by hands or traveling crane. To unscrew lower end cover and fixed pins; to lower the lower end cover.(the center of excitation end lower cover shall be lower as 550mm) 3.2.4.3 To uninstall fan vane at steam side, installing location for each fan vane, nut and washer shall be labeled with permanent mark. Each set shall be covered with cloth and placed in special toolset. 3.2.4.4 To lift rotor with traveling crane at turbine and excitation sides, and dismantle special tools used for lifting rotor, then move traveling crane towards excitation side, and stop when the distance between coupling end surface of turbine end and outer end surface of stator reach 210mm. 3.2.4.5 To lift rotor with traveling crane at excitation side. 3.2.4.6 To place tools those protect core from generator excitation side to core, and fix the sliding board on the housing of stator at steam side to avoid displacement of this sliding board. To connect journal sliding block handle to the journal of rotor at steam side, and place it above the journal. 3.2.4.7 To connect two proper sliding blocks, and the central spacing shall be 100mm, to connect fiberglass rope at front and rear end to prevent from being drawn out during sliding operation, to use bamboo stick to help it go into the location where the stator steam is near to the rotor retaining ring. 3.2.4.8 To fix the proper sliding block at end coupling with front side fiberglass rope, and add spacer strip between those bearing head surfaces. 3.2.4.9 To choose a point for fixing from the prolonged line of rotor axis at excitation side, and mount a 5-ton electric chain hoist and wire cable, then fasten the wire cable at the traveling crane. 3.2.4.10 Through the manhole door at lower base, screw the bolts that are supporting eight orinated bar at the both ends of the base, and lock it with nuts. 3.2.4.11 To lift rotor with tow-side traveling crane, and check the gap around stator and rotor at steam and excitation ends with lamp-lighting method. 3.2.4.12 To draw out the rotor with chain hoist, when proper sliding block is closing to core of excitation side, and the distance between retaining ring of steam end and stator housing end surface is about 2340MM, put down the journal sliding block on the sliding board. 3.2.4.13 When the proper sliding block has been moved from core of excitation side, then take it out, and continue to draw out the rotor, and draw out the center of gravity of rotor from stator chamber. 3.2.4.14 To wrap the tools that protect the rotor proper slot wedge with metallic bar at the center of gravity of rotor, to wind the rotor a round every 300mm with two ф50mm,10m long wire cables, and lift up the rotor with traveling crane and try to look for the balancing position to make rotor located at the horizontal position, then draw out the whole rotor. During extraction of rotor, rotor steam end shall be hold by someone to prevent the end coil from being collided by rotor. During the extraction
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of rotor, stress on retaining ring, collector ring, fan ring and slot wedg emust be strictly prohibited. 3.2.4.15 After rotor being drawn out, place it on the special supporting holder, for the purpose of overhaul and test, the bigger tooth(north and south pole)must be kept upright. Wind scooper shall be blocked and covered with canvas. Journal and slip ring shall be coated with terylene. 3.3 Equipment overhaul technology and quality standards 3.3.1 Notes to be paid attention prior to entering the stator chamber of generator. 3.3.1.1 Rubber board shall be placed inside the stator chamber and under end coil to avoid foreign substance entering into the core and air duct, and prevent end coil from being damaged. 3.3.1.2 All staffs who are going to enter the chamber must be prohibited to wear nail shoes or hard-soled shoes. Little metal wares such as key, knife and watch shall not be allowed . 3.3.1.3 Tools and materials that are used in the chamber (especially for metal) must be registered and be checked after work is done. Special personnel must be responsible for this. 3.3.1.4 The voltage of working lamp for lighting in chamber must be lower than 36V. 3.3.1.5 Smoking and fire are strictly prohibited in the stator chamber. If fire is necessary, it must be approved by relevant departments, and fire-fighting measures must be taken. 3.3.1.6 After everyday work is finished, the both ends shall be covered with canvas. 3.3.1.7 When overhaul work for stator is done, special personnel shall be responsible for inspecting. No foreign substance shall remain in the chamber. 3.3.2 Overhaul for stator of generator 3.3.2.1 Protection during overhaul of generator stator 3.3.2.1.1 After end cover is dismantled and stator is drawn out, the generator must be covered with canvas, and treated against dust, dampness, dew and being frozen in accordance with requirements. 3.3.2.1.2 All the holes leading into the generator must be blocked tightly to avoid rodents. 3.3.2.1.3 During overhaul and reassembly, foreign substance must be prevented from entering into stator water ways and core ventilating ducts. 3.3.2.2 Overhaul for stator of generator Item Technology of overhaul Quality standards 1 Reverse purge for Before reverse flush, blowndown for water water pressure shall be water circuit tank must be carried out, and filter gauge 0.25MPa. Generator stator shall be replaced. after shutdown 2 Test before major For items and standards for test, please overhaul refer to pre-test regulation 3 Sweep and Purge stator end winding with The surface of winding shall inspection for end compressed air, for oil filth, clean white be clean and smooth without winding of stator cloth soaked with cleaning liquid shall be oil filth, varnished membrane used to clean, metal or sharp object must shall be shining and complete without expansion and crack, be strictly prohibited to clean the oil filth insulation shall be free of breakage. Bus bar and slot shall be in good conditions without electric discharge trace like white powders.

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4 Check stator end winding binding pad and its fastener

5 To check insulated water leading pipelines

6 To check manifold

Check whether Band and binding of end winding are loose, and shape-fitting pad is complete. Check whether Inner supporting ring, adjustable binding ring and fixing nuts are fastened, for looseness and abrasion shall be treated accordingly. End supporting holder, cone loop bolts shall be fastened. To check whether various locking plates are locked perfectly. Check whether water leaking trace and surface abrasion exist at both junctions of insulated water leading pipelines. If filth is suspected to deposit on the pipeline inner wall, it shall be dismantled for cleaning. To check whether manifold is firm, and pad fastened bolts are complete, and displacement ,

Pad and bindings shall be free of displacement and looseness. There is no abrasion between pad and winding. Various fixing bolts shall be free of looseness, locking plate shall be locked tightly.

Water leading pipeline shall be mounted carefully without water leakage and abrasion.

Manifold shall be mounted tightly, and component shall be complete. The insulation of manifold to earth shall be good.

7 Air tightness and flow rate test for internal water system of stator 8 To check stator core

For details, refer to appendix A and D.

Stator core shall be purged and cleaned out. Then check whether teeth lamination is fastened, and ventilating duct is smooth,. And check whether ladder-shaping lamination at both end of core is fixed firmly without breakage and overheating. Siliconized plate shall be free of burrs and lodging. During inspection, if looseness of core is found, then insulated plate shall be planted into the loose part to back it; for burr case, it shall be removed and smoothed and coated with insulating varnish to avoid the short-circuit of core; when rust is found on the core surface, it shall be removed and coated with insulating varnish.

Ladder-shape core at both sides shall be pressed tightly and be free of burrs, looseness and overheating. Core teeth shall be complete without breakage. Core shall be free of partial discoloration caused by overheating, and the surface shall be free of water rusty trace, oil filth and powder caused by insulation abrasion.

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9 To check slot wedges of stator

To check whether slot wedge of stator is fastened in the slot, and whether there are discoloration, getting separated or damage on it. To check whether the straightness of corrugated plate is satisfied with requirements. To check the fastening situation of through bolts and nuts of stator core by hammering method one by one, and check the insulation resistance of bolts and nuts mentioned above one by one. To check the the fixing bolts of stator gap isolating ring, and make sure those bolts shall be free of looseness and bend, the thread shall be free of damage To check the junction between stator winding and leading wire, and make sure there is no water-leaking trace. If it can not be confirmed, insulation shall be opened for inspection. To check whether the fixation of leading wire is firm, and is worn out, and whether the fixture is loose or being detached. To check the situation of junction between outlet bushing and transition leading wire, and check the insulating layer is in good conditions, and whether thre is electric discharge or leaking trace or oil filth existing on the insulating surface. To check and clean outlet bushing of generator, and make sure there is no crack and breakage, to check the the junction between porcelain and flange, where shall be free of crack. And check whether the fixation between bushing and outlet cover is fastened firmly and reliable, whether oil is accumulated inside the outlet cover. To check whether the bolts that connect outlet cover and stator proper are firm and reliable.

The surface of slot wedge shall be in good conditions. To check the straightness of corrugated plate, and make sure that the max difference of seven holes shall be within 0.15mm-0.50mm. The noise of nuts shall be normal, and insulation resistance of through bolts shall be more than 100MΩ The fixation of bolts shall be free of looseness and bend.

10 To check through bolt and nut of stator core and insulation resistance to ground 11 To check stator fixing bolts of steam clearance isolating ring 12 To check leading wire of stator winding

The junction between stator winding and leading wire shall be free of water-leaking trace. The fixation of leading wire shall be firm without abrasion. Fixtures used for fastening shall be firm and reliable.

13 To check and sweep wire outlet bushing and wire outlet cover of generator

14 To check end

To clean out oil filth accumulated on
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The junction between outlet bushing and transition leading wire shall be in good conditions, and the insulating surface shall be free of electric discharge, leaking trace and oil filth. The outlet bushing of generator shll be free of crack and breakage. The junction between porcelain and flange shall be free of crack. The fixation between bushing and outlet cover shall be firm and reliable. Inner outlet cover shall be cleaned carefully without any foreign matters. The connecting bolts between outlet cover and stator proper shall be fastened firmly and reliable. Various components shal be

cover, guard plate, air-conducting ring and pedestal

15 To conduct a comprehensive cleaning and inspection for stator

various components, and check whether there is any deformation and welding crack on various parts, and whether the fastening bolts have been damaged. To wash the conjunction surface between stator housing and end cover, and various sealing glue hole as well as sealing slot of end cover with acetone. To smooth out the scratches on junction surface with hoe if necessary. After complement of stator overhaul, the stator chamber, end part and outlet cover shall be cleaned out thoroughly. The internal wall of stator chamber, end winding, leading wire and structural parts surface and back as well as water manifold surface shall be coated with insulating varnish. However, the insulating water-leading pipelines shall be covered instead of painting.

clean without defect. Sealing slot shall be clean without accumulated filth. The junction surface shall be smooth without burr and scratches.

Various part shall be kept clean without foreign matters.

3.3.3 Overhaul for rotor of generator 3.3.3.1 Protection during overhaul of generator rotor. 3.3.3.1.1 After rotor has been drawn out from the generator, it shall be wrapped tightly with plastic membrane to prevent dust and foreign matters from entering into the ventilating duct, especially for end winding. 3.3.3.1.2 Rotor proper bigger tooth surface can be used as supporting surface for placement of rotor. The retaining ring can not be used as lifting and supporting point. 3.3.3.1.3 During rotor has been placed outside, rotor winding and retaining ring must be treated to avoid dampness and condensation especially, to prevent insulation from being damped and corrosion of retaining ring.(applicable methods including: a. placing desiccant or mounting air dryer; b. installing hot-air fan to keep the temperature of rotor winding and retaining ring more than ambient temperature about 5℃). 3.3.3.1.4 Journal can be coated with non-acidic lubricating grease, and then install protective clap for journal to avoid being damaged or rust. 3.3.3.1.5 During process of rotor extraction as well as the whole overhaul, attention shall be paid to prevent foreign matter from entering into ventilating duct, which could cause the blockage of air hole. Items Overhaul technology Quality standards 1 Rotor test For test items and standards, please refer to preventive test regulations. 2 Check and clean To purge rotor with dry compressed air Surface of rotor shall be clean rotor proper and and conduct inspection and cleaning. without oil filth; ventilating hole ventilating hole of When oil filth is found, it shall be rubbed of rotor winding shall be without dust with clean white cloth soaked with smooth rotor winding cleaning liquid, metal or object with sharp accumulated. end is strictly prohibited for this case.
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3 Check rotor central ring and retaining ring

4 Measure clearance between rotor retaining ring and rotor proper.

Therefore, check ventilating hole of rotor winding by compressed air. Check carefully whether the junction between retaining ring and rotor proper, between retaining ring and central ring embedded part are normal. To measure relative axial displacement between retaining ring and proper, between retaining ring and central ring. Then check the function of ring key Measure it along upper round of rotor proper, the clearance shall be within 0.36mm—1mm.

5 Check slot wedge of rotor

6 Check balancing block

Check whether slot wedge of rotor is fixed appropriately and no displacement along axial direction, and check whether the ventilating hole is aligning with the ventilating duct. To check and ensure the balancing block and proper balancing screws shall be firmly fixed without displacement

\The embedded junction part between retaining ring and rotor proper, between retaining ring and central ring shall be in good conditions without any abnormality and axial displacement. Ring key shall function properly. The difference between the measured value and previous values shall not be significant. Clearance along the circumference shall not exceed 0.05mm. The tension of slot wedge of rotor shall be appropriate without any displacement

7 Disassembly and inspection for fan vans

8

Metal

flaw

Check whether the fan vane is intact before disassembly and tap it with little hammer to judge the looseness caused during assembly by means of sound. Check whether the number and label on the vane are complete and matched, special torque spanner shall be used during disassembly. Each vane dismantled and the original adjusting washers, tab washers, vane-fixing screws and nuts shall be screwed together and placed in a special toolkit for storage. After vane hase been dismantled, fan base ring at rotating shaft shall be checked for displacement. Check whether there is crack, scratches and other abnormality existing in the vane and base ring. For unqualified vane, replacement shall be taken. Procedure and quality standards shall be
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The balancing block shall be fixed firmly without any displacement. The balancing screws shall be free of looseness. During disassembly of vane, each vane shall be matched with the original adjusting washer, tab washer, vane-fixing screws and nuts. Mixing assembly shall be prohibited. The embedding part between fan base ring and rotating shaft shall be free of displacement. The fan vane and base ring shall be free of crack, scratch and other abnormality.

Metal crack detection shall be

detection for retaining ring, central ring and fan vane. 9 Inspection for bottom turn of winding end.

10 Inspection for grounding brush

11Air-tight test for rotor 12 Ventilating test for rotor ventilating hole.

performed in accordance with regulations and standards concerning metal supervision. To check deformation and displacement of bottom coil from central ring round hole with reflector. In-turn padding strap shall be intact without any damage. Check whether pad block is complete. If severe deformation or insulation damage is found, test shall be conducted to find out whether the in-turn short-circuit is existing. Retaining ring can be taken off if necessary. Clean grounding copper braided brush with detergent and check whether brush is intact, whether braid is connected firmly with brush without breakage, overheating and discoloration. Brush be able to move freely in the brush-holder, and the clearance shall be within 0.1-.2mm, replacement can be performed if necessary. For details, please refer to appendix C For details, please refer to appendix B

performed according to standards concerning metal supervision. Bottom coil shall be free of displacement and deformation. The inturn padding strap shall be intact. Various pad block shall be complete.

The surface shall be suitable, smooth without abrasion, and with appropriate elastic pressure.

3.3.4 Overhaul for collector ring and brush holder Items Overhaul technology 1 Inspection for Check situation of collector ring surface, collector ring. the uneven degree shall not exceed 1mm. and the elipticity shall be less than 0.05mm. To check whether the surface is smooth or have crushed damage, burn, concave-convex points. To check whether the spiral air-conducting groove and ventilating hole is smooth and free of dust gathering. To check whether insulating brushing under collector ring is intact. Filth accumulated on the collector ring shall be cleaned with tooth picks firstly, then insulating detergent shall be employed for purge and sweep. A layer of constant-temperature solidifying epoxy varnish shall be coated on the collector side and insulating brushing surface.
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Quality standards The surface of collector ring shall be in good conditions and clean without any filth. The measured insulation resistance shall be satisfied with relevant requirements.

2 Inspection for brush holder, brush box and brush.

Check and ensure there is no crack in the brush box, and internal wall is smooth., and spring pressure is in good conditions. To check whether the sliding surface of brush is smooth and free of scratches and burning trace. And check the brush side for blocking trace. To check whether the fixing screws are fixed tightly and the junction between brush and brush braid is well connected without looseness. To check whether the brush braid is free of overheating and breakage. To check whether the brush can move freely in the brush box. The clearance shall be within 0.1-0.2mm. during displacement for brush, the same type, same series brushes shall be chosen for use. The new brushes shall be ground and the contacting surface shall not be less than 70%.

Brush box shall be good conditions without any defect. The spring pressure shall be satisfied with requirements. The surface of brush shall be in good conditions and be able to move freely inside the brush box.

3.3.5 Overhaul of hydrogen cooler of generator Items Technology of overhaul 1 Disassembly of To shut off the water valve at hydrogen hydrogen cooler cooling pump outlet, then open the drainage valve to drain out the water gathering inside the pipelines and hydrogen cooler. Therefore, close the inlet valve of hydrogen cooler. And make preparation for hydrogen cooler lifting procedure. To dismantle the bolts that connect hydrogen cooler to cooling outer cover, then mount the special tools for extraction of hydrogen cooler, and draw out the hydrogen cooler. Place the hydrogen cooler to designated location after it being lift out. 2 inspection and After hydrogen being disassembled, outer cleaning for through flake shall be purged with two hydrogen cooler gauge-pressure steam. Those deformed flakes shall be corrected. To wash and clean water tank and end plate of hydrogen cooler, for components that are suffering varnish flaying, anti-corrosive varnish shall be painted again. 3 Inspection and To clean the cooper tubing with special
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Quality standards Dismantled bolts shall be placed and kept in special toolkit for storage. During disassembly, attention shall be paid to mark positions of those fasteners and supports.

The hydrogen cooler shall be free of oil filth or other filth. The through flake shal be in order and complete. The water tank shall be clean without filth. Sealing pad shall be abound of elasticity without breakage. Inner wall of cooper tubing

cleaning for cooper tubing of hydrogen cooler

4 Hydrotest hydrogen cooler

for

5 Air-tight test for hydrogen cooler

washng tools one hole by one hole. During washing, the action shall be performed gently to avoid causing leaking due to violent operation. If hard sediment found in the cooper tubing, chemical acidic washing method is optional too. Rust-proof varnish shall be painted on the internal part and both sides of cooler water tank, and cooler shall be assembled after all the sealing rubber have been replaced. After assembly of hydrogen cooler, hydrotest shall be conducted. During test, various parts of hydrogen cooler shall be examined for leakage. If leakage is found at expansion part of copper tubing, re-expanding operation can be performed. For the case of invalid re-expanding operation or blister or crack found in the tubing, it is allowed to block the both ends of the tube with wedges. However, the number of blocked tubes of each hydrogen cooler shall not exceed 5% of total number. After assembly of hydrogen cooler, air-tightness test shall be conducted too.

shall be smooth without any filth and damage.

Standards of hydrotest: water pressure set as 0.8 Mpa. Time set as 30Min

6 Reassembly hydrogen cooler

of

To reassemble the hydrogen cooler in reverse order.

7 Inspection for hydrogen-supplying system.

Sweep and clean hydrogen-supplying system, and valves, flange and fastening bolts of carbon dioxide pipelines. To clean and check silica gel hydrogen drer and silica gel dryer. To check cool hydrogen dryer.

Standards for test: air pressure set as 0.5Mpa, time set as 6h, allowable pressure drop shall not exceed 0.0004Mpa. To check the mounting conditions of hydrogen cooler connecting bolts and gasket carefully for the air tightness of generator. Pipelines shall be free of crack and deformation. Gasket shall be intact without aging. Bolts shall be fastened firmly and evenly. Valve shall be free of internal and outer leakage. Silica gel shall be dry and clean. Dryer shall be sealed perfectly. Various valve shall function freely without leakage. The performance of refrigeration shall be good.

3.4 Reassembly of equipment and quality standards
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3.4.1 Notices: 3.4.1.1 The whole overhaul work for stator and rotor shall be finished and accepted before reassembly. 3.4.1.2 All the objects that are used for blocking the ventilating hole of rotor slot wedge shall be removed. 3.4.1.3 Tools must be returned totally prior to reassembly. No tools or other foreign matters remain inside the stator chamber. Insulating water-leading pipe shall be checked and ensured there isno bend or damage on it. 3.4.1.2 Bolts and tools required for reassembly shall be delivered to the site. 3.4.1.5 During installation, check whether various parts and equipments are matched with those marks made before disassembly. 3.4.2 Assembly of generator Items Procedure of overhaul Quality standards 1 Work before rotor 1 Hydrogen cooler shall be mounted installation inside the cooling outer cover, and cooling water inlet and outlet pipeline shall be resumed. 2 Resume the connection between stator winding water circuit and outer cooling water system. 3 Place lower half inner end cover at steam and excitation side to the pedestal end cover, and place lower half end cover at both ends to the pedestal. 4 During fastening the lower half end cover, firstly fasten 5 bolts: 2 for horizontal position, 1 for vertical central line, 2 for 45 degree. 5 Confirm that there is a 0.8mm clearance between lower half end cover and pedestal. 2 Rotor installation Reverse to rotor extraction procedures. 1 During stator and rotor 3 Reassembly of 1 During fan vane assembly, vanes shall clearance re-measurement, it other parts be reassembled following positions of locating dowel in the fan base ring, ensure shall be conducted according to vertical and horizontal four that vane angle is satisfied with points, error shall not exceed requirements of design. Each fan vane, range specified by nut, adjusting washer, tab washer and etc the shall be reassembled according to original standards 2 The clearance between position, and be fastened tightly with air-conducting ring and fan torque spanner. Mounted vane shall be vane shall be satisfied with tapped with little hammer to check requirements specified by whether it is firmly fastened. Finally, lock drawings, and error shall out the lock slice. 2 After axis has been aligned, re-measure within range specified by standards. clearance between rotors.
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4 Reassembly of collector ring brush

3 Reassemble upper half inner end cover of both steam and excitation sides, lock screws evenly at housing end cover surface, then lock out the lock blade. 4 Reassemble air-conducting ring at steam and excitation sides, and insert locating dowel, then evenly fasten screws that connect inner end cover surface, as well as screws that connect upper and lower air-conducting ring junction surface, then re-check clearance between air-conducting ring and fan vane, and compare it with that before disassembly 5 Before end cover is in place, add HDJ—892 sealing filler to the end cover sealing slot.(the same shall be done for lower half end surface ) 6 Clean horizontal junction surface of lower half end surface, add sealing filler to sealing slot. 7 Move upper end cover in place, the clearance between it and pedestal shall be 0.8mm. 8 Install positioning bolts and bolts that connect upper junction surface, however, do not lock those bolts tightly. 9 Fasten those bolts at upper and lower end cover circumference alternatively until outer end cover is tightly stuck to pedestal. 10 Assemble and fasten those bolts that connect end cover inner junction surface, and fasten those bolts that connect end cover outer side junction surface by means of heating. 11 After those work mentioned above is finished, fill sealing filler to junction surface of end cover, and use special glue-filling gun to fill those holes until all the holes to be filled is full with glue. 1 Assemble the two half brush holders in accordance with original position, adjust radial clearance between brush holder and collector ring. Meanwhile, adjust edge distance between brush holdler and collector ring at two sides. Therefore, fasten those anchor botls of brush holder.
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3 When sealing filler is adding into sealing slolt, check smoothness of junction face, it shall be free of salient point and greasy dirt, and inner part of sealing slot shall be cleaned up. 4 Check and ensure inner end cover, and bolts that connect fan vane are fastened tightly.

1 Check and ensure radial distance between lower edge of brush holder and collector ring surface shall be even, which should be within 2 ~ 3mm.

2 Check whether electric brush is available. 3 After generator air-tight test is finished, assemble the noise isolating cover, and determine the clearance between nois isolating cover baffle plate and shaft.

2 Contacting surface between new groud brush and collector ring shall not be less than 75 %, there shall be 0.1~0.2mm clearance between brush and brush box, brush shall move freely without jamming. Spring pressure applying to each brush shall be even, which shall be within 0.015~ 0.02Mpa. brush braid shall be unbroken and fixed firmly 3 Clearance between noise isolating cover baffle plate and shaft shall be satisfied with requirements specified by drawings, which shall be within range of 0.10~0.21mm.

3.5 Integrated test for generator 3.5.1 Air-tightness test for rotor of generator 3.5.1.1 Preparation for test 3.5.1.1.1 Tools and materials: 1Mpa pressure gauge, oxygen, absolute alcohol and special tools. 3.5.1.1.2 To replace the sealing rubber gasket at both ends of rotor central hole. 3.5.1.2 Test standards(for static state of rotor): to fill rotor with 0.5Mpa clean compressed air for six hours. In case that ambient air pressure and temperature can be kept stable, the allowable value of air pressure drop shall not exceed 0.05MPa. 3.5.2 Sealing examination for the whole generator system 3.5.2.1 Test standards: The testing pressure shall be 0.4Mpa. testing time shall be 24hours. The allowable volume of air leakage shall be 3.2m³/day.

3.5.2.2 Conditions required for test 3.5.2.1 Connection of pipelines must be satisfied with the actual situation of normal running of generator. 3.5.2.2 Sealing oil control system shall be put into service, the difference between air side oil pressure and internal air pressure shall meet with requirements of normal operation. Oil pressure of hydrogen side and that of air side must be kept balanced. The same oil level must be kept for sealing oil tank during each reading and recording. 3.5.2.3 Working states of valves and instruments of hydrogen, oil and water control system, shall be consistent with actual status of normal operation of generator. 3.5.2.4 No water shall be filled into the Internal Cool water system of generator and hydrogen cooler. The air exhausting valve must be open. 3.5.3 Test procedures: 3.5.3.1 Open inlet valve of compressed air to let air enter into the generator chamber slowly, at this
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time, the sealing oil system shall be put into service. 3.5.3.2 Special person shall be sent to monitor the pressure gauge during air conducting. And Freon valve shall be open for flush. 3.5.3.3 When Freon filled into the generator has reached 3.4-4kg, stop filling operation. 3.5.3.4 Keep filling with compressed air to increase the pressure upto 0.4Mpa, and then close air inlet valve. 3.5.3.5 Check with soap solution, and then with halogen leak detector carefully. 3.5.3.6 After pressure has been kept stable, then record the time, and keep the status for 24 hours. During this period, halogen leak detector shall be employed to check carefully, and variation of pressure shall be recorded every 1 hour. 3.5.3.7 After 24 hours, according to pressure variation, to calculate air-leaking volume, and determine whether it is satisfied with test standards. 3.5.3.8 If test results are satisfied with requirements, exhaust compressed air from generator. 3.5.3.9 Comprehensive inspection for test work shall be conducted, and the working site shall be cleaned up. 3.5.4 Formula for sealing test verification: 3.5.4.1 When U-type mercury differential pressure gauge and precise pressure gauge are adopted △V=V[(P1+B1)/(273+θ1)-(P2+B2)/(273+θ2)]×(θ0/P0)×(24/Δt) 3.5.4.2 When oblique differential pressure gauge is adopted △V=0.00024VΔP/Δt Symbol explanation V-------Air volume filled in the generator, M³ P0-------Absolute atmospheric pressure at given conditions,P0=0.1Mpa θ0------Absolute atmospheric temperature at given conditions, θ0=273+20=293K P1-------Air pressure inside generator when test begins, Mpa; θ1------Average temperature of air in the generator when test begins,℃ B1------------Absolute atmospheric pressure when test begins, Mpa; P2-------Internal air pressure when test is over, Mpa; θ2------Average internal air temperature when test is done, ℃; B2------------Atmospheric absolute pressure when test is finished, Mpa; ΔP------------Pressure drop of oblique differential pressure gauge from test startup to end, Pa; Δt------------Time used for test, h; 3.6 Electrical test carried out after overhaul Test items 1. Measure resistance of three-phase stator coil to ground and phase-to-phase insulation resistance with 2500V water cooling special megohm meter. Procedures and quality standards Compared with factory set values, stator three-phase winding resistance to ground and phase-to-phase insulation resistance shall be free of significant variation, absorption ratio ≥1.6, polarization index ≥2.0, three-phase unbalancing coefficient shall be less than 2. stator coil DC leakage and DC voltage withstand: testing voltage shall be 2.5

2. Test stator coil DC leakage and DC voltage withstand, testing voltage is defined into 5 increasing stages by every 0.5 time rated voltage, to read leaking current for each stage

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during 1min suspension, and when voltage reaches to 2.5 Times of rated voltage, the leaking current shall not increased following prolongation of time. At rated testing voltage, the difference between each phase leaking current shall not exceed 1000% of the minimum; for those 20μA cases, the difference between each phase shall not be apparently significant.

3. AC impedance and power loss inside rotor chamber test, to measure impedance values at various voltage, the difference between the maximum and the minimum shall be less than 5% of the maximum. The difference between inside and outside of chamber shall be less than 2%.

times of rated voltage, the difference of each phase leaking current shall not exceed 100% of minimum; for case under 20μA, the difference between each phase shall be free of significant variation. And leaking current shall not increase along with prolongation of time. According to p69 of manual provided by Dongfang Electric Machinery Works concerning, it is recommended: “if Dc voltage withstand test is conducted while stator water circuit has not been purged out, it may cause insulating water-leading pipe due to electric discharge happening inside insulating water-leading pipe. DC leakage test has been conducted for multiple times at non-water status in the factory. Therefore, the on-site DC leakage test can be skipped. Test for AC impedance and power loss inside rotor chamber, to measure impedance values at various voltage, the difference between the maximum and the minimum shall be less than 5% of the maximum. The difference between inside and outside of chamber shall be less than 2%.

3.7 Test for generator startup 3.7.1 After generator set startup, measure AC impedance and power loss of rotor winding at different rotating speed respectively. During barring state, at 500、 1000、 1500、 2000、 2500、 3000r/min, measure rotor winding insulation resistance and DC impedance( to skip critical rotating speed) respectively. 1000V megohm meter can be used for the former, and the measured value for 1min shall not be less than 0.5MΩ. compared with previous measured value, the latter shall be free of significant variation. 3.7.2 No-load characteristic test for generator shall be conducted after overhaul. This test can be conducted with main transformer. To adjust rotor current under rated rotating speed which is set as 3000r/min, to increase maximum of rotor voltage up to 1.1 times rated voltage, therefore, decrease rotor current to zero gradually, during this process, to read 9~10 points, more points shall be chosen around rated voltage, then prepare no-load characteristic curve, and compare it with factory setting or acceptance test, the difference shall be within the range of measuring error. 3.7.3 At rated rotating speed, measure bearing vibration under non-excitation idle running state and no-load running state with excitation. Along 3 directions of bearing block (horizontal, vertical and axial direction relative to rotor central line), measured double amplitudes shall not exceed 0.03mm. 3.7.4 Shaft voltage test High internal impedance (no less than 100kΩ/V)AC voltage meter shall be used for measurement for no-excitation idle running case and no-load with excitation case. When bearing oil membrane of turbine generator has been short-circuited, usually, voltage at both end shafts of rotor shall be equal
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to that between bearing and pedestal. Resistance of turbine generator bigger shaft to ground shall be less than 10V generally. 4 Maintenance during operation 4.1 General principles A set of effective and preventive maintenance work can reduce unexpected disruption during generator operation. Basic principles of maintenance work during operation include: be familiar with which parts of generator need to be corrected periodically, which parts are apt to fail, and how to evaluate working conditions of those parts. 4.2 Maintenance of collector ring and carbon brush 4.2.1 Items of routine inspection 1) Brush at collector ring shall be free of fire trace. If sparks are found, treatment shall be performed according to appendix. 2) Carbon brush inside brush box shall be free of oscillation or blockage, and can move upwards and downwards freely in the brush box. 3) Brush braid shall be intact and well contacted, and be free of overheating. If getting black or burn is found, replacement for carbon brush shall be performed. 4) To check whether pressure of carbon brush is normal; The pressure that each carbon brush applies to collector ring shall be equal basically, and the carbon brush pressure shall be 1. 45f 士 20%/ each one(weighed by spring balance. Otherwise, the spring shall be replaced. 5) Abrasion and loss of carbon brush. Dimension of carbon brush is: 25.4X38.1 X102 (mm), allowable abrasion length for carbon brush is 60mm; to check whether the brush block edge has shed off, if carbon brush is worn out severely or brush block has shed off, replacement for carbon brush must be performed 6)To check carbon brush for flutter Such reasons like unbalancing abrasion of collector ring, loose carbon brush, generator set vibration and etc may cause flutter of carbon brush. If flutter happens, carbon brush must be taken out from brush box to check whether it is being damaged. Cause shall be found out and eliminated. 7) To check whether there is filth gathering at brush box and brush holder. If filth is found, it shall be cleaned with brush or purged with blower. 8) The surface of collector ring shall be free of discoloration and overheating, and the temperature shall not exceed 120℃. 4.2.3 Replacement for carbon brush Generally, at the same period, only one brush holder is allowed to being replaced for each brush holder support, and model of new carbon brush shall be consistent with that of old one. different carbon brushes shall not be mounted on the same collector ring. New carbon brush shall be trimmed according to the shape of replaced carbon brush, and shall be ground at the model whose diameter is equal to that of collector ring, the contacting surface between carbon brush and collector ring shall exceed 70% of total area. Personnel with experience shall be responsible for replacement work for carbon brush. Safety warning: When replacement for brush holder is performed during operation, the operator must not touch two live components with polarity at the same time 4.2.3 Half-year or shutdown inspection 1) To clean brush block and internal wall of brush box, and those carbon powder or filth accumulated on collector ring surface and carbon brush holder. 2) After shutdown, check coarseness of collector ring surface as well as circumference jumping,
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treatment shall be performed if normality has been found. 3) To replace polarity of collector ring periodically( the abrasion of anode is different from that of negative electrode) 4) Check painting conditions around collector ring insulating trunk, if damaged, re-painting and cleaning for surface shall be performed. 4.3 Maintenance of cooler 4.3.1 Clean hydrogen cooler periodically, if sediment happens on cooling water pipes, it will lower the effectiveness of cooler. Cleaning interval for cooler can be determined according to experience. In principle, if cooling water with normal temperature and flow rate can not guarantee appropriate cooling air temperature, cooler shall be cleansed. 4.3.2 During shutdown, dismantle the cooler, and clean its water pipeline with special nylon brush. 4.4 Inspection after short-circuit fault 4.4.1 If generator has suffered from a severely fault, such like three-phase short-circuit, tow-phase short-circuit, or single-phase short-circuit to ground, or severe asynchronous closing, generator stator winding and rotor shall be examined carefully and immediately. 4.4.2 During faults mentioned above, mechanical force applied to stator end winding will cause more stress on end winding and its supporting components than normal conditions. One timely inspection will possibly bring one minor overhaul, if timely inspection has been ignored, it may result in more severe damage when second fault happens. 4.4.3 Important inspection items are listed as follows: Displacement of stator base The fastening status of end winding, to check end band, supports, annular leading wire and etc, and ensure three is no looseness. To check whether there is crack on bar surface and HV outlet bushing. To check whether oil baffle cover and bearing shell is damaged. For those asymmetric short-circuit, check rotor surface, especially for retaining ring junction surface. To check for negative sequence burning damage, Others. These faults mentioned above will result in large torque in rotating shaft and coupling, which may cause deformation of coupling pin. Inspection for those components is very necessary. 5 Maintenance during shutdown 5.1 Long-term shutdown During long-term shutdown, when hydrogen has been discharged and sealing oil system and other auxiliary system have been shut down, corresponding maintenance items are listed as follows: 5.1.1To exhaust hydrogen inside generator Purge each “dead zone” at pedestal top with clean compressed air, and discharge hydrogen inside. 5.1.2 To drain out water gathering in stator winding water circuit 1) Open blow-down outlet below steam and excitation end manifolds, to let water gaterhing in manifold to run out. 2) Dismantle water inlet and outlet pipelines, and cover water outlet flange of steam end with cover plate, then connect air hose to water inlet flange of steam end. Compressed air shall be clean without oil or dust content. 3) Open compressed air switch, and purge out water from stator winding water circuit with compressed air, and repeat this operation for several times until purged air is free of water mist. 4) Then choose vacuum extraction method, to draw out water that is gathering in stator winding water circuit and difficult to being purged out.
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5.1.3 Maintenance of stator winding water circuit To avoid oxidation of internal wall of hollow copper wireless, stator winding water circuit shall be washed and flushed slowly by nitrogen through water inlet and oulet. After that, seal water inlet and outlet flange. 5.1.4 Maintenance of hydrogen cooler Cleaning of hydrogen cooler; after cleaning is finished, drain out the water storage well and purge water pipeline with compressed air to avoid corrosion. For details, please refer to “maintenance of cooler” 5.1.5 To prevent condensation formed inside generator It is recommended to dismantle the two manholes, where air heater or air dryer shall be mounted to kept internal air dry continuously. For the location Air heater or air dryer to be mounted, it shall be considered that air recirculation be able to pass through all spaces inside generator. By this mean, internal air will be kept dry under various climate without condensation, which can avoid danger that are caused by insulation being moisturized or stress corrosion happening on retaining ring. 5.1.6 Maintenance for rotor During long term shutdown, if the rotor is kept inside the machine for a long time, it shall be rotated in a angle as 90 degree every three days to prevent being deformed permanently due to bend. 5.1.7 Safety measures Hydrogen alarming system shall be kept in operation. It is recommended that the hydrogen supplying pipelines shall be removed during shutdown period to avoid hydrogen being supplied accidentally 5.2 Short-term shutdown 5.2.1 General principles During short-term shutdown, generator is still filled with hydrogen, and oil sealing system is in normal operation. Stator winding water cooling system shall be kept in normal operation. General preventive measures shall be taken to prevent dew condensed inside and to ensure adequate sealing oil volume. Low conductivity of cooling water of stator winding shall be kept to realize restart as soon as possible. Therefore, the following parameters shall be monitored and recorded periodically. Parameters: Temperature and pressure of sealing oil Purity, humidity and pressure of hydrogen Possible leakage hydrogen gathered in enclosed bus Stator cooling water temperature and conductivity 5.2.2 Sealing of hydrogen To keep sealing oil system in normal operation, and keep sealing oil pressure higher than hydrogen pressure 0. 056NPa, and oil temperature higher than that 30℃, to ensure hydrogen is being sealed tightly. 5.2.3 Purity of hydrogen To check hydrogen purity periodically, and keep internal hydrogen purity above 95% by means of supplying fresh hydrogen. 5.2.4 To prevent condensation Relative humidity inside generator shall be controlled below 50%, which can prevent condensation formed inside generator. During shutdown, relative humidity inside generator will vary with ambient temperature of generator. Periodical detection, and measure relative humidity inside generator when ambient temperature has dropped more than 8℃. If relative humidity inside generator is found too
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high, appropriate hydrogen shall be discharged, and some dry hydrogen shall be supplied form hydrogen-supplying system to lower the relative humidity inside generator. 5.2.5 Cooling water of stator winding Fill water into stator winding to realize water circulating cooling, and temperature of cooling water shall be higher than that internal hydrogen 5℃ or above, to prevent water content in hydrogen frome being condensed on the stator winding, meanwhile, which can avoid oxidation and corrosion of hollow copper wire of stator winding. Conductivity of stator winding cooling water shall be checked periodically, and water conductivity in water tank shall be kept within range that is specified in “technical data summary”. 5.2.6 Maintenance of cooler To avoid corrosion of cooling water pipe or sediment, water with lower flow rate shall be kept passing through the cooler. Additionally, the cooler needs to be washed and flushed twice every week with large flow water. 5.2.7 Safety measures Hydrogen alarming system shall be at working status. Hydrogen exhaust device in bearing lubricating oil system shall be at working conditions, by which hydrogen that are leaking from generator and mixing into oil returning system can be possibly extracted. For winter shutdown case, if generator is likely to being exposed below freezing(room temperature <5℃,water shall be drained out from cooler to avoid being frozen. Temperature of stator windng circulating water shall be kept above 5℃ to avoid being frozen.

Appendix A Air-tight test for internal water system of generator stator
1. Equipments, instruments and materials: 1 Halogen defect detector 2 U-type mercury differential pressure gauge or precisive pressure gauge 3 Thermometer 4 Atmospheric pressure gauge 5 Freon 6 Nitrogen or compressed air 7 Pipelines, valves and such accessories required for test 2. Requirements for test 2.1 If water remains inside winding, it shall be purged with compressed air and treated by drying process. 2.2 Compressed air used for test must be treated through drying and filtering process. 2.3 Air inlet valve shall be closed tightly during air-tight test, and gas source can be separated if necessary. 2 . 4 Temperature-measuring points shall be deployed as more as possible, temperature of air-leaking ratio can be calculated by its average temperature. 3. Test method 3.1 Open compressed air inlet valve to let gas enter into stator winding slowly, pay attention to monitor indications showing on pressure gauge. 3.2 When pressure reaches to 0.1Mpa, fill with about 1Kg Freon. 3.3 After Freon has been filled, continue to fill with compressed air to increase pressure upto 0.52Mpa, and then close inlet valve.
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3.4 Carefully check all points where leakage are likely to happen with halogen defect detector, and pay attention to variation of pressure. 3.5 If no leakage is found, discharge internal compressed air and conduct air-tight test. 3.6 Open inlet valve, and increase pressure upto 0.4Mpa, after pressure being stable for 2 hours, record time and pressure, and kept for 24 hours. 3.7 Within 24 hours, pressure variation shall be recorded every hour, and in the meantime, atmospheric pressure and temperature shall be recorded too. 3.8 If test is done and qualified, discharge gas inside stator winding 3.9 Conduct a comprehensive inspection for test work, and clean up working site. 4. Formula used for calculating air-tight test for stator winding water system 4.1 Test standards: leaking pressure drop for 24 hoursΔPd≤0.2%P1,P1 is defined as initial test pressure 4.2 Formula: ΔPd=24/Δt[(P1-P2)+(B1-B2)+(P1+ B1) (t2-t1)/(273+t1)] P1------- gauge pressure at test starting, Mpa; P2 ------ gauge pressure at test ending, Mpa; B1------------ atmospheric absolute pressure at test starting, Mpa; B2------------ atmospheric absolute pressure at test endting, Mpa; t1------ average temperature at test starting, ℃ t2------ average temperature at test ending, ℃ ΔPd ------leaking pressure drop for 24 hours,Mpa; Δt------------ time consumed by test, h;

Appendix B Ventilation test for generator rotor
1. Preparation before test 1.1 Rotor surface and various air ducts shall be cleaned up prior to test, such as removing metal powder, insulation powder and ust, shard and etc. 1.2 Test site must be kept clean, and indoor air shall be clean. 1.3 Beginning with rotor excitation end retaining ring, label vents of various air zones respectively. Air zone that are close to excitation side shall be labeled as the first air zone, and the remained shall be labeled according to this sequence. 1.4 Special volute air inlet chamber rotating shaft and rotor end retaining ring, and pressure meter detector shall be connected to special volute air inlet chamber. 1. 5 All the vents at rotor slot shall be blocked with special plugs.(except outlet vents that conduct air from end) 2. Test method for ventilating duct located at rotor end. 2. 1 Start blower, by means of changing inlet area of blower, adjust air pressure inside volute air inlet chamber within 950-1050Pa. 2. 2 Connect with tangential photoelectric anemometer, and plug anemometer inlet into the air outlet hole, record stable reading shown on indicator, and fill in the log. 2. 3 Check various air ducts of rotor excitation end and steam end by method mentioned above, and then block all the air outlet holes with plugs. 3. Test for air duct of rotor slot 3. 1 Start blower, by means of changing inlet area of blower, adjust air pressure inside volute air inlet
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chamber within 950-1050Pa. 3.2 Taken out special plugs used for inlet and outlet vents of air duct test, connect with tangential photoelectric anemometer, and plug anemometer inlet into the air outlet hole, at this time, indicating shall be zero. 3.3 Connect air outlet vent of rubber hose to air inlet hole, meanwhile, avoid air leakage, stable reading shown on indicator, and fill in the log. 3.4 After test, put those special plugs that have been taken out back to original holes, and check various air duct of rotor slot by method mentioned above. 4. Test standards 4.1 Average equivalent air speed of air duct at rotor coil end shall not be less than 10m/s, air duct whose equivalent air speed is lower than 6m/s is not allowable. Number of air ducts whose equivalent air speed is lower than 8m/s shall be no more than 10, for each end and each slot ,the number shall be no more than 1. 4.2 Average equivalent air speed of air duct at rotor coil slot shall not be less than 4m/s, number of air duct whose equivalent air speed is lower than 2.5m/s shall be no more than15 in the whole rotor internal slot. For each slot, the number shall be no more than 2, and the two ducts shall not be next to each other. 5. Equipment and materials required for test 1 A blower that total pressure shall not be less than 1600Pa, and flow rate shall not be less than 0.9m³/s 2 A set of type FS tangential photoelectric anemometer with starting air speed not more than 0.4m/s 3 A set of special volute air inlet chamber 4 A set of pressure gauge within 0-2000Pa 5 6m rubber hose with inner diameter as 25mm 6 Adequate special plugs used for blocking vent. record

Appendix C Air-tight test for generator rotor
1. Conditions prepared before test 1.1 Draw out rotor and place it on the special supporting frame. 1.2 Deliver nitrogen and Freon to test site. 1.3 Mount special gag used for rotor air tightness, and pay attention to sealing. 1.4 Connect pipelines that are used for filling nitrogen and Freon, and install precise pressure gauge. 2. Test procedures 2.1 Open nitrogen inlet valve, and stop filling when pressure has increased up to 0.2Mpa. 2.2 Open Freon inlet valve, and fill in with 0.2-0.3Kg Freon 2.3 Then re-open nitrogen inlet valve, to increase pressure up to 0.5Mpa. 2. 4 Check leaking locations with halogen defect detector, especially for rotor conductive screws and sealing joints. 2.5 Record time and pressure when pressure is stable, and kept it for 6 hours. 2.6 Test standards: pressure drop shall not exceed 0.05Mpa.
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Appendix D hot water flow test for internal water system of stator
1. This test is regarded as one method that are adopted to find out whether severe blockage happens on any part of generator stator internal water system.. 2. Equipment and instruments 2.1 Copper-cupron thermocouple 2.2 Temperature recorder (minimum separating value shall be 0.1℃, and numbers of channels shall be more than that of all thermocouples to be measured, and measuring time shall be less than one minute) 2.3 Outer water system of generator 3. Preparations before test 3.1 Bind thermocouple joints to the outer surface of middle part of water outlet end insulating water-leading pipe, outer surface of each insulating water-leading pipe must be mounted with thermocouple. 3.2 Each thermocouple shall be coated with thermal insulation materials to ensure thermocouple is insulated from air. 3.3 Connect thermocouple with temperature recorder point by point, and check the evenness of thermocouple readings. 4. Test method 4.1 Start stator outer water system device, and adjust the differential pressure between stator water inlet and outlet main to normal value of operation, and at this time, measure temperature of various points to be measured 4.2 By means of self-circulation and steam heating, increase testing temperature over that of cooling water above 10℃ 4.3 When temperature of measuring points is close, shut down operation of device of stator outer water system, and record temperature of various points to be measured. 4.4 Keep outage status for 30 min, during this period, record reading of temperature every 5 min. 4.5 After status of out of service is ended, open cooling water valve swiftly, and fill stator internal water system with cooling water. Start water pump to maintain stator internal water system running at differential pressure as normal operation, meanwhile record readings of temperature. Thereafter, recording shall be performed every 1 min. 4.6 After water has been circulated for 15min, and temperature of thermocouple becomes stable, stop running and recording temperature of thermocouple. 4.7 Process data and draw time-temperature curve for each insulating water-leading pipe. 4 . 8 It can be determined clearly whether cooling water is passing through the insulating water-leading pipe by comparison with curves. 5. Precaution: 5.1 This test shall be conducted after stator internal water system flush has been finished. 5.2 If channels of temperature recorder is not enough, it can be conducted in groups, however, number of groups shall not be more than 3. 5.3 When some results is doubtful, test can be conducted again with more higher temperature of
- 29 -

water.

Appendix E cause of spark happening on carbon brush and ways to eliminate sparks
Possible cause and nature of appearance of sparks 1、Carbon brush is poor ground, and its surface has not been put into service totally 2、Model of carbon brush is unsatisfied with requirements, or different carbon brushes have been used on the same collector ring 3、Inappropriate position of carbon brush holder 4 、 Clearance between brush box and collector ring is unsatisfied with requirements 5、 Connection between carbon brush and leading wire, between leading wire and terminal become loose, and sparks happen partially; the contacting resistance of carbon brush leading wire circuit is too large, which cause load being allocated unevenly. 6 、 Spring becomes hot and soft with elasticity loss; pressure of carbon brush are uneven. 7、Length of carbon brush is too short after abrasion 8、Swing of spring inside brush box, or spring can not move freely due to filth accumulated in brush box, sparks increase as load increases Ways to eliminate it Carbon brush shall be re-ground, or generator is put into service with light load for long term until being ground well. Check carbon brush type, and replace it as that specified by manufacturer or suitable carbon brush qualified by test. Re-adjust position of brush holder, align its axis parallel to that of collector ring Re-adjust clearance between brush box and collector ring, to make it being satisfied with requirements issued by manufacturer. Check contacting conditions between carbon brush and brush braid and whether various screws located in leading wire circuit have been fastened tightly, and whether contact is in good conditions.

Replace spring, normal pressure for spring shall be 1.45Kgf±20%/ per unit Replace the carbon brush, usually, length of brush block shall not be less than 40 mm. Check conditions of carbon brush inside brush box, whether it can move freely upwards and downwards, replace swinging carbon brush and sticking carbon brush. Cleanse brush block and carbon powder between brush boxes, the clearance between carbon brush and brush box shall be controlled within 0.1~ 0.mm Find out cause of vibration and eliminate it; during shutdown, check status of collector ring, turning treatment shall be performed if necessary.

9、Vibration of carbon brush, sparks vary with intensity of vibration, possible reasons may be as those described below: uneven abrasion of collector ring, or uneven surface, excessive jumping, as well as excessive vibration of generator set

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Part II generator set protection and automatic devices
Chapter I verification manual about microcomputer type generator protection devices
1 Overview

Digital multi-function protection device produced by Siemens is selected for protection for India NAGARJUNA 2×600MW coal-fired generator set, the whole generator protection is designed as dual-set configuration, with simple wire connection, reasonable design, and convenient commission. Various faults and abnormal operation conditions can be reflected sensitively, with swift output speed, it is suitable for protection for large-scale generator and transformer. Type 7UM6225 has been selected for generator, type 7UM6111 for excitation transformer, type 7SJ6021 for rotor current protective device. Software stored in system can provide various different protection function, which can be solely chosen, started and set for protecting certain equipment function. Allocation for input and output of various tripping signals, alarming signals and logical signals can be resolved through appropriate software configuration. Main protection functions are listed as follows: 1. Differential protection for generator 2. Stator grounding protection for generator 3. Out-of-step protection for generator 4. Negative sequence protection for generator 5. Generator over-load protection 6. Generator backup over-current protection 7. Generator low impedance protection 8. Generator excitation-loss protection 9. Generator reverse-power protection 10. Generator over-excitation protection 11. Generator over-voltage protection 12. Generator frequency protection 13. Generator sudden voltage protection 14. Generator inter-turn protection 15. Rotor current over-load protection 16. Excitation transformer over-current protection 17. Excitation transformer over-load protection 2 Technical characteristics 2.1 The SIPROTEC 4 7UM62 is a numerical machine protection unit from the -7UM6 Numerical Protection" series. It provides all functions necessary for protection of generators, motors and transformers. 2.2 Characteristics
- 31 -

2.2.1 7UM62 General Features Powerful 32-bit microprocessor system. Complete digital processing of measured values and control, from sampling and digitalization of measured quantities to tripping circuit breakers or other switchgear devices. Total electrical separation between the internal processing stages ofthe device and the external transformer, control and DC supply circuits of the system because of the design of the binary inputs, outputs, and the DC converters. Simple device operation using the integrated operator panel or by means of a connected personal computer running DIGSI. Continuous computation and display of measured quantities. Storage of fault messages and instantaneous or rms values for fault recording. Continuous monitoring of measured values as well as of the hardware and software of the device. Communication with central control and memory storage equipment via serial interfaces, optionally via data cable, modem, or optic fibre lines. Battery-buffered clock that can be synchronized with an IRIG-B (via satellite) or DCF77 signal, binary input signal, or system interface command. Statistics: Recording of the number of trip signals instigated by the device and logging of currents switched off last by the device, as well as accumulated short circuit currents of each pole of the circuit breaker. Operating Hours Counter: Tracking of operating hours of equipment under load being protected. Commissioning aids such as connection check, field rotation check, status display of all binary inputs and outputs, and test measurement. The relay SIPROTEC 7SJ602 is used as definite time 2.2.2 Features The scope of functions depends on the ordered version. The following functions may not be implemented in the device all at the same time. Processor system with powerful 16-bit-microcontroller. Complete digital measured value processing and control from data acquisition and digitizing of the measured values up to the trip and close decisions for the circuit breaker. Complete galvanic and reliable separation of the internal processing circuits from the measurement, control and supply circuits of the system, with analog input transducers, binary input and output modules, and d.c./d.c. converter. Simple setting and operation using the integrated operation panel or a connected personal computer with menu-guided software, connected via the front port. Storage of fault data, storage of instantaneous values during a fault for fault recording. Continuous monitoring of the hardware and software of the relay as well as supervision of the sum of the four current inputs. Optional serial interface with a communication module: RS232, RS485, or optical fibre. Transmission protocols according to IEC 60870-5-103 or Profibus DP or Modbus RTU/ASCII, or connection of a modem or RTD-box are possible. Circuit breaker control and measured value indication and transmission are possible, depend on the ordered version. 3. Overhaul period and verification items 2.1 Overhaul period
- 32 -

Comprehensive overhaul (major overhaul) shall be performed after this device has been put into service for one year, thereafter partial overhaul(minor overhaul) shall be practiced according to equipment operation status, major overhaul shall be performed every six years. 2.2 Items of minor overhaul 2.2.1 Inspection for power supply 2.2.2 Calibration for graduation 4.3 Inspection for setting values 4.4 Inspection for output 4.5 Inspection for completeness of plug-in components. 4.6 Calibration of clock 5 Standard items of major overhaul 5.1 Cleaning 5.2 Inspection for terminals 5.3 Test for protection static state. 5.4 Various test in minor overhaul 5.5 Test for protective linkage 5.6 Simulator test 4 Verification regulations for generator protective devices 4.1 Notice proceedings 4.1.1 Turn off the switch of power supply before plug or pull the module to make the DC power supply off. Never plug or pull the module with electricity to prevent the component from damage. 4.1.2Special measures must be adopted during the module plug or pull to avoid component damages by static electricity of human body. 4.1.3 Fix earthing screw firmly to the earth lead before other connections achieved 4.1.4 High voltage may occur between the circuit and component used for connecting the DC power supply or testing or experiment. 4.1.5 Risky high voltage may occur on the device even if the DC circuit switch off. (The energy storage capacitor discharge) 4.1.6 The testing capacity cannot exceed the limit number specified in the technical datasheet for every device. 4.2 Machinery appearance and configuration (Qualified√) NO. Content Conclusion 1 I Fix of protection equipment meet the requirement of drawing Appearance of insert piece and quality of welding meet the requirement 2 of techniques Fixed e,Ino Ioose, no ob "ous damage and distortion on the protection 3 equipment Marking is clear and right, the terminal of protection equipment 4 connected reliable 5 Switch, keyboard should be operated flexible with right handle 6 No dust on the screen 7 Easy to move the door of screen and open the lock 8 No lacquer drop and knock and fish tail inside and outside of the screen 9 All kinds of markings and signs are clear 4.3 Device and connection inner screen (Qualified √)
- 33 -

No. 1

2 3

Test content Conclusion Check if the nameplate, model of relay meets the design requirement. Pay special attention on rating current of the assistant power supply and mutual-inductor Check if the actual connection meets the requirement of design drawing and the connection is fixed firmly Check if the protection screen and all shielding cable earthed well

4.4 Insulation test (insulation resistance) 4.4.1 Remove all the connection points on the screen, with the DC circuit short circuit on the both input points and input points of AC circuit. 4.4.2 Measure the insulation resistance about all independence circuits to earth and among all independence circuits with ZC25-3 500V Megameter Insulation resistance (MΩ) No. Items 1 2 3 4 5 6 7 8 9 10 DC circuit to earth AC circuit to earth Open circuit to earth Out circuit to earth DC circuit to AC circuit DC circuit to open circuit DC circuit to out circuit AC drcuit to out drcuit AC circuit to out circuit Open circuit to out circuit

Note: not less than 5 MΩ with secondary circuit, not less than 10 MΩ without secondary circuit. 4.5 Power performance 4.5.1 Protection Function List Code/Model ANSI Code setting value function Setting value Remarks Address 87G Generator differential protection 2001~2063 64G1 F1(2)1 7UM6225-6EB92-0C B0-LOD 64G2 64R 78 46 49 50/51 21 40 32R 24 59 95%Starer earth protection 100%Stator earth protection Rotor earth protection Out-of-Step protection Neg. overcurrent protection Overload protection Undervoltage seal-in O/C Protection Impedance protection Loss-of-Field protection Reverse power protection Overexcitation protection Overvoltage protection
- 34 -

5001~5005 5301~5311A 6101~6107A 3501~3512 1701~1707 1601~1616A 1201~1207A 3301~3317A 3001~3014A 3101~3105A 4301~4314 4101~4107A

32F 81 50/27 60 95 60 50/51 50151/67 49 F1(2)3 7SJ6021-5EBg0-1FA0-L OD 49

Low power protection Frequency protection

3201~3206A 4201~4215

F1(2)2 7UM6111-5EB92-0AA0LOD

Inadvertent energization 7101~7105 protection VTt fuse failure 8001 Generator Intertum protection 5001~5005 v'r3 fuse failure Exc.transf O/C(I>) protection Exc.transf OIC(I>) protection Exc.transf ovedoad protection Rotor overload protection 8001 1201~1207A 1301~1303 1601~1616A 2701-2707

4.5.1.1 Information about protection equipment of electric generator (7UM6225-6EB92-0CB0-LOD) Manufacturer SIEMENS Model 7UM6225-6EB92-0CB0-L0D Serial No. Software version Mounting position Purpose Generator protection 4.5.1.2 Information about protection equipment of electric excitation transformer (7UM6111-5EB92-0AA0-LOD) Manufacturer SIEMENS Model 7UM6111-5EB92-0AA0-LOD Serial No. Software version Mounting position Purpose Excitation transformer protection 4.5.1.3 Information about protection equipment of electric motor current (7SJ6021-5EB90-1FA0-LOD) Manufacturer SIEMENS Model 7SJ6021-5EB90-1 FA0-LOD Serial No. CP080500027 Software version V 3.6 7 Mounting position 10CHA01-F1(2 Purpose Motor current protection )3 4.5.2DC power supply test Check if the magnitude and poladty of voltage meet the requirement by multimeter before the equipment electrified with DC. Check the DC control voltage of input circuit on relay according to the design requirement DC input: Theoretical value (Allowable deviation ±20%) Real value DC I Real value DC II 220V DC Test result: 4.5.3 LED and reset botton test Press the LED reset button to check if the light on the panel bright and the testing finished: Press the B1O black button the check if the yellow and red light are bright and the testing finished.
- 35 -

Test result: 4.5.4 Analog Input test 4.5.4.1 Input the setting of all function, parameters, fixed value according to the setting book 4.5.4.2 Category the required LED light, way out circuit, switching value input circuit according to the design or setting book or the requirement of user on-site. 4.5.4.3 Logic programmed according to the situation of field apparatus or the operation requirement 4.5.4.4Testof AC phase sequence and current, voltage input circuit linearity(Current,voltage error is less than 5%) F1(2)1 (7UM6226-6EB92-0CB0-LOD): Sampling value of currentM1(side1) S1 IL1 S1 IL2 S1 IL3 1.0A 20A 5.0A Sampling value of Current M2 (side2) 1.0A 2.0A 5.0A Sampling value of voltage 20V 40V 63.5V F1(2)2 (7UM6111-5EB92-0AA0-LOD): Sampling value of Current O.IA 0.5A 1.0A Sampling value of voltage

S2 ILl

S2 IL2

S2 IL3

UL1

UL2

UL3

IA

IB

IC

UL1

UL2

UL3

20V 40V 63.5V F1(2)3 (7SJ6021-SEB90-1 FA0-LOD): Sampling value of Current IA IB IC 0.1A 0.5A 1.0A Test result: 4.5.5 Protection function test Requirements: the error of operated value can not over the 5% of setting value,if the start value of operated for differential protection is 0s, the value of 1.5 times is about 35ms and the allowable error of additional relay time is 1% of setting value for time. The test result is shown as secondary value 4.5.5.1 F1(2)1 (7UM6225-6EB92-0CB0-LOD): 1. Test data of differential protection (87G) Setting value Test result (A) Differential protection pickup 1=0.3 I/In0 SIDE1 A SIDE1 B SIDE1 C SIDE2A SIDE2 B SIDE2 C 87G T=0s
- 36 -

Diff>>

1=4.0 I/In0 SIDE1 A SIDE1 B SIDE1 C SIDE2 A SIDE2 B SIDE2 C T=0s Test 2 Test 4 point

Slope 1 S1=0.25 Calculate point Test point 1 Calculate point 2 Basic point 1 0 Slope 2 S2=0.5 Calculate point Test point 3 Calculate point 4 Basic point 3 2.5 I/In0

point

2. Test data of 95% stator earth pmtecion (59N/67GN) Protection Setting value Operated value Setting time U0> 3 Test data of Out-of-Step protection (78): Protection Setting value Operated Setting value Ch1 1 I1> 120% 12< 20% First point Second point Test Data Borderline of Operated state impedance operated Za Zb No-operated operated No-operated Zc operated No-operated Zd operated No-operated 4. Test data of negative sequence protection (46) Protection Setting time 1 Setting time 2 Setting time 3 46 th 200s 50s 22.22s Operated time 1 Operated Ch1

Operated time

Setting Ch Operated Ch 2 2 4

Third point

Operated time 2

Operated time 3

5. Test date of overload protection (49) Protection Setting time 1 Setting time 2 Setting time Operated Operated 3 time 1 time 2 49 th 5618.64s 3866,09s 2990.78s 6. Test data of Undervoltage seal-in O/C Protection protection(50/51) Protection Setting value Operated Setting time value
- 37 -

Operated time 3

Operated time

I> U<

5.19A 80V

3.5s

7. Test data of low resistance protection (21) Protection Setting value Operated Setting time value 3s I> 4.81A U< 88V

Operated time

8.Test data of Loss-of-Field protection (40) Angle of U/I Static state value 90° 0MW/-187.38MVAR 75° 60° 40° Setting value Calculate 50.26MW/-187.46MVAR 109.55MWl-189,63MVAR 177.75MW/-177.81 MVAR Φ1 80° Φ2

Dynamic value 0MW/-456.78MVAR 129.35MW/-505.93MVAR

90°

Φ3

110°

Φl = arctan[(177.75-109.55)/( -177.81 +189.63)]=80.17° Φ2= arctan[(50,26-0)/( -187,46+187.38)]=89.94° Φ3=arctan[(129.35-0)/( -505.93+456,78)]=110.12° Tcharl (setting=10s) Operate Time Tchar2(setting Tchar3(setting=0.5s) =10s) T shot time(setting=2s)

9. Test data of reverse power protection (32R) Setting time Protection Setting value Operated value P> -1.26% 0.50(with Tsv) 10,00(without Tsv) 10.Test data of overexcitation protection (24) Protection Setting value Operated value 24-1 1.05 24-2 1.20

Operated time

Setting time lOs 3S

Operated time

11. Test data of overvoltage protection (59) Protection Setting value Operated value 59-1 126.5V 59-2 143.0V

Setting time 3s 0.5s

Operated time

12. Test data of forward power protection (32F) Protection Setting value Operated value P> 12.6%

Setting time 10s
- 38 -

Operated time

P<

5.1%

0.5s Setting time 300s lOs lOs lOs Operated time Operated time

13. Test data of frequency protection (81): Protection Setting value Operated value 81-1 48Hz 81-2 81-3 81-4 47Hz 49Hz 51Hz

14. Test data of Inadvertent energization protection (50/27): Protection Setting value Operated value Setting time I> 1.1A 5s UI< 55V 15. Test data of VT1 fuse failure (60): Protection Threshold voltage Setting value 60 IOV

Result

U2 >0.4 U1 I1 <0.2 I2

4.5.5.2 F1(2)2 (7UM6111-SEB92-0AA0-LOD) 1. Test data of Generator Interturn protection(95) Protection Setting value Operated value Setting time U0> 7.5V 0.5s 2. Test data of VT3 fuse failure (60) Protection Threshold voltage 60 10V

Operated time

Setting value

Result

U2 >0.4 U1 I1 <0.2 I2

3. Test data of Exc.transf O/C(I>) protection(50/51) Protection Setting value Operated value Setting time l> 2.05A O.3s 4. Test data of Exc,transf O/C(I>>) protection(50/51/67): Protection Setting value Operated value Setting time I>> 5.73A 0.05s

Operated time

Operated time

5. Test date of Exc.transf overload protection (49) Protection Setting time 1 Setting time 2 Setting time Operated Operated 3 time 1 time 2 49 alarm 252.98s 149.32s 1og.10s 49 trip 297.62s 175.67s 128.35s
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Operated time 3

4.5.5.3 F1(2)3 (7SJ6021-5EB90-1FA0-LOD). 1. Test date of rotor overload protection(49) Protection Setting time 1 Setting time 2 Setting time 3Operated Operated time 1 time 2 49 alarm 1267.30s 593.21s 407.24s 49 trip Test result: 4.5.6 Binary Input Function test (Right '√") 4.5.6.1 F1(2)1 (7UM6225-6EB92-0CB0-LOD): Name Test method Device F 1(2)1 Cooling water loss Short circuit between X1(2)30--1 BI1 and X1(2)30--22 I&C trip (from ETS) Short circuit between X1(2)30-2 and BI2 X1(2)30--23 Steam valve closed Short circuit between X1(2)30--3 BI3 and X1(2)30--24 AVR excitation system Short circuit between X1(2)30--4 BI4 faulty and X1(2)30--25 Spare Short circuit between X1(2)30--5 BI5 and X1(2)30--26 Spare Short circuit between X1(2)30--6 BI6 and X1(2)30--27 Spare Short circuit between X1(2)30--7 BI7 and X1(2)30--28 20Hz generator fault Short circuit between X1(2)30--8 BI8 and X1(2)30--29 Spare Short circuit between X1(2)60--8 BI13 and X1(2)60--18 spare Short circuit between X1(2)60--9 BI14 and X1(2)60--19 Spare Short circuit between X1(2)60--10 BI15 and X1(2)60--20 4.5.6.2 F1(2)2 (7UM6111.SEB92-0AA0-LOD) Name Test method DeviceF1(2)2 spare F1(2)3 output BO1 BI1 spare F1(2)3 output BO2 BI2 Rotor ovedoad alarm F1(2)3 output BO3 BI3 Rotor overload Trip F1(2)3 output BO4 BI4 spare Short drcuit between X1(2)30 - 11 and BI5 X1(2)30-- 32 spare Short circuit between Xt30-- 12 and BI6 X1(2)30 --33
- 40 -

Operated time 3

1490.94s

697.89s

479.11s

Result

Result

spare

Short circuit between X1(2)30--13 and X1(2)30--34

BI7

4.5.6.3 F1(2)3 (7SJ6021-SEB90-1FA0-LOD): Name Test method Device F1(2)3 spare Short circuit between X1(2)30-14 and BI1 X1(2)30-35 spare Short circuit between X1(2)30-- 15 and BI2 X1(2)30 -- 36 spare Short circuit between X1(2)30-16and BI3 X1(2)30- 37 Test result: OK 4.5.7 Output Function test (Right "√" ) OUTPUTS links -Fll BO 17& -F1(2)2 BO 17 CLASS A TRIP K161 (LOCKOUT RELAY) K161A K161B K161C K166 K611 K612 Close L1(2)01 Close L1(2)02 Close L1(2)03 Close L1(2)04 Close L1(2)05 Close L1(2)06 Close L1(2)09 Close L1(2)10

Result

Corresponding teminal X 166:1-4 X1(2)66:2-6 X1(2)66:3-8 X1(2)66:10-13 X1(2)66:11-15 X1(2)66:12-t7 X1(2)66:19-21 X1(2)66:23-26

State CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE OPEN CLOSE

Result

X1(2)66:24-28

CLOSE

Close L1(2)l1 X1(2)6625-30 Close X1(2)66:32-35 L1(2)12 Close X1(2)66:33-37 L1(2)13 Close X1(2)66:34-39 L1(2)14 X1(2)66:41-43 Close LL1(2)9 Close L1(2)20 X1(2)66:53-55 X1(2)66:57-59
- 41 -

CLOSE CLOSE CLOSE CLOSE OPEN CLOSE CLOSE

X1(2)66:61-63 Close L1(2)07 Close L1(2)08 Close L1(2)15 Close LL1(2)6 X1(2)66:65-67 X1(2)66:69-71 X1(2)66:73-75 X1(2)66:77-79 X1(2)66:81-83 X1(2)66:85-87 X1(2)70:21-22 X1(2)71:3-4 X1(2)71:5-6 X1(2)72:3-4 X1(2)72:5-6 X1(2)76:1-2 X1(2)76:3-4 X1(2)76:5-6 Close L1(2)01 Close L1(2)02 Close L1(2)03 Close L1(2)04 Close L1(2)05 Close L1(2)06 X1(2)66:1-4 X1(2)66:2-6 X1(2)66:3-8 X1(2)66:10-13 X1(2)66:11-15 X1(2)66:12-17

OPEN CLOSE OPEN CLOSE CLOSE OPEN CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE

-Fll BO 18 CLASS B TRIP K162(LOCKOUT RELAY) K162A K162B K162C K166 K611 K612

X1(2)66:19-21 Close L1(2)09 Close LL1(2)0 Close Llll Close LL1(2)2 Close LL1(2)3 X1(2)66:23-26

OPEN CLOSE

X1(2)66:24-28

CLOSE

X1(2)6625-30 X1(2)66:32-35 X1(2)66:33-37
- 42 -

CLOSE CLOSE CLOSE

Close LL1(2)4 Close L1(2)20 Close L1(2)07 Close L1(2)08 Close LL1(2)5 Close LL1(2)6

X1(2)66:34-39 X1(2)66:41-43 X1(2)66:57-59 X1(2)66:61-63 X1(2)66:65-67 X1(2)66:69-71 X1(2)66:73-75 X1(2)66:77-79 X1(2)66:81-83 X1(2)66:85-87 X1(2)70:23-24 X1(2)71:3-4 X1(2)71:7-8 X1(2)72:3-4 X1(2)72:5-6 X1(2)76:9-10 X1(2)76:11-12 X1(2)76:13-14 X1(2)76:15-16

CLOSE OPEN CLOSE OPEN CLOSE OPEN CLOSE CLOSE OPEN CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE

Close L1(2)01 Close L1(2)02 Close L1(2)03 -Fll BO 19 CLASS C TRIP K163(LOCKOUT RELAY) K163A K164B K163C K166 K611 K612 Close L1(2)04 Close L1(2)05 Close L1(2)06

X1(2)66:1-4 X1(2)66:2-6

X1(2)66:3-8 CLOSE X1(2)66:10-13 X1(2)66:11-15 CLOSE CLOSE X1(2)66:12-17

X1(2)66:19-21 Close L1(2)09 X1(2)66:23-26
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OPEN CLOSE

Close L1(2)10 Close L1(2)11 Close L1(2)12 Close L1(2)13 Close L1(2)14

X1(2)66:24-28

CLOSE

X1(2)6625-30 X1(2)66:32-35 X1(2)66:33-37 X1(2)66:34-39 X1(2)66:41-43 X1(2)70:25-26 X1(2)71:3-4 X1(2)71:9-10 X1(2)72:3-4 X1(2)72:5-6 X1(2)76:19-20 X1(2)76:21-22

CLOSE CLOSE CLOSE CLOSE OPEN CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE

STARTING 400KV CBF

Close L1(2)17 -Fll BO 20&-F1(2)2 BO 19, K167 Close L1(2)18 -Fll BO 1 K701 (Frequency Alarm) -Fll BO 2 Protection

X1(2)66:45~7 X1(2)66:49-51 X1(2)71:17-18 X1(2)72:7-8 X1(2)71:19-20 X1(2)72:9-10 X1(2)71:21-22 X1(2)72:11-12 X1(2)71:23-24 X1(2)72:13-14 X1(2)71:25-26 X1(2)72:15-16 X1(2)71:27-28 X1(2)72:17-18 X1(2)66:97-99 X1(2)71:29-30 X1(2)72:19-20 X1(2)71:31-32
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K702 (Neg-sequence Protection Alarm) -Fll BO 3 K703 (Overload Alarm) -Fll BO 4 K704 (Loss-of-Field CH1 Alarm) -Fll BO 5 K705 (Out-of-Step CH2 Alarm) -F1(2)1 BO 9 K706(Overvoltage/ Overexcitation Alarm) -F1(2)1 BO 11 K707 (VT1 Fuse Failure) -F1(2)1 BO 12

Close L1(2)23

K708 (External Signal Input Trip) -F1(2)1 BO 13 K709 (100%Stator Earth-Fault Alarm) -F1(2)1 BO 14 K710 (100%Stator Earth-Fault Trip) -F1(2)1 BO 15 K711 (1-3Hz Rotor Earth-Fault Alarm) -F1(2)1 BO 16 K712 (1-3Hz Rotor Earth-Faut Trip) -F1(2)2 130 1 K713(Generator Interturn Protection Trip) -F1(2)2 BO 2 K714 (VT3 Fuse Failure) -F1(2)2 BO 3 K715(EX.Trans.Overcurrent Protection Trip) -F1(2)2 BO 4 K716(EX.Trans.Overload Protection Alarm) -F1(2)2 BO 5 K717(RotorOverload Protection Trip) -F1(2)2 BO 6 K718(RotorOverload Protection Alarm) KB02(PRO.OC Supply Loss) -Fll BO 6(Reduce Load) -Fll BO 7(Reduce Excitation) -Fll BO 8(Sepuence Trip) Close L1(2)21 Close L1(2)22 Close LL1(2)9

X1(2)72:21-22 X1(2)71:33-34 X1(2)72:23-24 X1(2)71:35-36 X1(2)72:25-26 X1(2)71:37-38 X1(2)72:27-28 X1(2)71:39-40 X1(2)72:29-30 X1(2)71:41-42 X1(2)72:31-32 X1(2)71:43-44 X1(2)72:33-34 X1(2)71:45-46 X1(2)72:35-36 X1(2)71:47-48 X1(2)72:37-38 X1(2)71;49-50 X1(2)72:39-40 X1(2)71:51-52 X1(2)72:41-42 X1(2)71:1-2 X1(2)72:1-2 X1(2)66:89-91 X1(2)66:93-95 X1(2)66:53-55 X1(2)70:17-18 X1(2)66:53-55 X1(2)70:19-20 X1(2)71:13-14
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CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE

CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE

-Fll BO 10(SYS.A 7UM6225 Relay Trip) -F1(2)2 BO 18(Sepuence Trip) Close LL1(2)9 -F1(2)2 BO 3(SYS.A 7UM6111 Relay Trip) -F1(2)1(7UM6225 Fault)

-F1(2)2(7UM6111 Fault)

X1(2)71:15-16

CLOSE

Test result: 4.5.8 Test of the trip matrix and the LED setting. 4.5.8.1 The relay LEDs settings and test result: a)-F1(2)1 relay F1(2)1 Test result LED 1 Differential Pro.Trip LED 2 95% SEF/100% SEF Pro.Trip LED 3 1-3Hz REF Pro.Trip LED 4 Forward Low Power TRIP LED 5 Out-of-Step Pro,Trip LED 6 Neg. Seq. O/C Pro.Trip LED 7 Overcurrent/Overload Pro.Trip LED 8 Inadvertent energization Pro.Trip LED 9 Low Impedance Pro.Trip LED 10 Loss-of-Field Pro.Trip LED 11 Reverse Power Pro.Trip LED 12 Overexc./Overvol. Pro.Trip LED 13 O/U Frequency Pro.Trip LED 14 VT1 Fuse Failure b)-F1(2)2relay F1(2)2 Test result LED 1 Generator Interturn Pro.Trip LED 2 Exc.transf O/C pro.Trip LED 3 Exc.transf Overload pro.Trip LED 4 VT3 Fuse Failure LED 5 Rotor overload pro.trip LED 6 LED 7 c) -F1(2)3 relay F1(2)3 Test result LED 1 Rotor overload pro.alarm LED 2 Rotor overload pro.trip LED 3 LED 4 4.5.8.2 The relay trip matrix and result: The trip matrix is attached in this test report. Test result: 4.5.9 Other tests 4.5.9.1 The red LED H12 will be ON when any TRIP by SYSTEM A. 4.5.9.2 The yellow LED Hll will be ON when there is any internal error in System A such as DC Power Loss, trip circuit supervision, relay self-test, relay power off. Test result:
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Chapter II verification manual of UN5000 excitation system
1. Overview UNITROL5000-Q5S-O/U251-S6000 。 Static excitation equipments produced by Dongfang ABB company are selected as excitation system of India NAGARJUNA 2×600MW coal-firing generator set, and equipment model is UNITROL5000-Q5S-O/U251-S6000 In this excitation system, synchronous generator terminal voltage can be regulated by controlling excitation current that can be realized through SCR rectifier. The whole system can be divided into five main function modules: excitation transformer, two set of separated excitation regulator, SCR rectifying unit, excitation initializing unit and de-excitation unit. In the static excitation system, excitation power is supplied from generator terminal, magnetic current of synchronous generator is supplied from excitation transformer, field breaker and SCR rectifier. Excitation transformer will lower generator terminal voltage to input voltage required by SCR rectifier, and also provide electric insulation between generator terminal voltage and field winding, meanwhile which can function as rectifying impedance of SCR rectifier. SCR rectifier is responsible for converting AC current into controlled DC current. During excitation initializing progress, magnetism-charging energy comes from residual voltage of generator. After input voltage of SCR rectifier has reached to 10V~20V, SCR rectifier and excitation regulator can be put into normal service, thereafter AVR will take control of soft excitation initialization. After synchronization, excitation system can work under AVR model, regulating generator terminal voltage and reactive power, or can work under superposition model, such as constant power factor adjustment, constant reactive power regulating and so on. Additionally, it can accepted group forming command issued by power plant. In accordance with system requirements, excitation regulator adopts four-channel structure: tow automatic channels and tow independent backup channels(EGC). Each automatic channel consists of main controlling board(COB) and measuring unit board (MUB) basically, and shall be regarded as an independent processing system, which features with generator terminal voltage regulating, excitation current regulating, excitation monitoring function and programmable logic control software. Each independent manual channel includes an independent expanding gate control board (EGC) as backup channel. When fault happens in automatic channel, it can be switched to independent manual channel(EGC) automatically. However, automatic channel can not be switched to manual channel manually. This set of static excitation equipment manufactured by Switzerland ABB company, features with simple hardware, abundant software, easily to realize modern control rules and multiple functions, good performance and convenient operation. 2.Technical parameters: Apparent output power Crest current MVA Crest voltage V V

A(20S) S

Rectifying cabinet AC power supply voltage: Adjusting method: PID Regulating accuracy: 0.2% Rated excitation voltage:
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Responding time:

Voltage regulating range: 0.9—1.1Ue Excitation initializing voltage: AC 230V

V

Rated continuous supplied excitation current DC 2000A No-load excitation voltage: V

No-load excitation current

A

Excitation transformer rated capacity: 7200KVA Voltage of excitation transformer impedance %

Excitation transformer ratio:22000/900V

The whole excitation system includes excitation transformer, +ER(automatic excitation regulating cabinet), +EG(rectifying cabinet), +EA auxiliary cabinet, and +EE(de-excitation cabinet) 3. Overhaul period and test items 2.1 Overhaul period A comprehensive inspection(major overhaul) for this device shall be performed after it has been installed and put into service for one year, thereafter, partial overhaul (minor overhaul) shall be carried out according to running conditions of equipment, and comprehensive inspection (major overhaul)shall be conducted every six years. 2.2 Overhaul items 2.2.1 Static test 2.2.2 Dynamic test 3. Static test 3.1 Appearance inspection and dust-cleaning for components During operation of excitation system, most faults can be diagnosed by system, however, for most components, such as excitation switches, rectifiers as well as control board, circuit board and etc, status variation can not be observed. Therefore, during shutdown and overhaul, conduct analysis according to running parameters that are recorded in daily inspection log, especially for varying curves that are reflecting status of excitation transformer, rectifying cabinet temperature and etc, to perform examination and maintenance for equipment. 3.2 Key sections to be checked including: 3.2.1 Inspection for de-excitation switches. 3.2.1.1 Check whether de-excitation switch(Q02) is stained with dust or dirt, or being damaged.

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Additionally, abrasion degree of contact shall be checked too. 3.2.1.2 Clean up dir and filth with hair brush and dry cloth, and polish those burnt places with abrasive paper if necessary, and lubricate sliding section with appropriate lube. 3.2.2 For de-excitation switch, Quenching pot shall be checked after short-circuit current has been cut off each time, and dust and soot gathering inside quenching pot shall be purged with compressed air. Pull out aviation plug specified in figure, and ensure excitation switch has been disconnected from rotor circuit. 3.3 Inspection for printed circuit 3.3.1 Contact and coordinate inspection items of commission period, because jumper and address setting shall be kept intact during operation, therefore main work shall focus on appearance inspection, wire connection examination and function verification. 3.3.2 To check whether there is dust gathering, under current situation, pay attention to keep environment of equipment operation clean, and cleanse dust accumulated on surface with hair brush or cleaner. Maintenance staff shall wear grounded wrist strap prior to work commencement, to release out electrostatic that may be carried by human body. Solvent shall not be used for cleaning for PCB. (normally, there shall be no dust or dirt accumulated on PCB. If PCB is stained, inspection shall be performed for current protection class IP. 3.4 Rectifying cabinet 3.4.1 SCR elements

(Based on temperature curve of rectifying cabinet, to determine whether dust-cleaning shall be performed) open plastic plate of rectifying cabinet with spanner, deal with those fragile screws and carefully. Because the limitation of thyristor mounting technology, it is recommended that dust stuck on the surface shall be purged with compressed air.

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3.4.2 Fan of rectifying cabinet Caused by some non-electrical reasons, for excitation system, rectifying cabinet is liable to fault. Especially after long-term operation, it is necessary to focus on inspection for fan, air damper, filter during shutdown and overhaul. Check whether filth is gathering on rectifier fan, whether air flow rate is normal and whether there is abnormal noise. It is impossible to add lube for fan bearing during running, therefore, fan shall be replaced when noise becomes louder. Attention:a、fan mounted on door of AVR cabinet shall be repaired after about 40,000 hours running. b、Rectifier fan must be repaired after about 25,000 hours running. Check whether dust is gathering in air filter (strainer), and replace for filter cartridge if it is found very dirty(periodical inspection and replacement shall be performed during normal operation) 3.4.2 Cooling fin Check cooling fin for filth, removed it with hair brush, cleaner and compressed air (the pressure shall not be too high). Solvent shall not be an option for cleaning. 3.4.3 DC and AC busbar and other electric elements During operation of generator set, surface of DC and AC busbar shall be stuck with dust, and it can be cleaned with hair brush and cleaner. Check the surface for rust, if found, clean it with special cleaning agent and paint with rust-proof coat. 3.5 Inspection for outer circuit connection, verification for signals and inspection for wire connection inside cabinet. 3.5.4.1 Wire connection between excitation and outer circuit. 3.5.4.1.1 Signals from excitation to thermal engineering( for signal name and connection position, please refer to annex 1 Work shall focus on fastening of terminals. Check whether there is parasitic circuit existing, and check insulation of key circuit is satisfied with requirements. 3.5.4.1.2 Check wire connection from excitation to protection panel, and fasten those terminals. 3.5.4.1.3 Check wire connection of each power supply of excitation, and measure whether voltage is satisfied with requirements. 3.5.4.1.4 Check connection from excitation to generator PT, CT terminal box and excitation transformer terminal box. 3.5.4.2 Verification for signals from excitation to outer circuit. 3.5.4.2.1 Verification with DCS signals
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3.5.4.2.2 Verification with signals of protection panel. 3.5.4.2.2.1 Both excitation outlet tripping protection circuit, and circuit for protecting tripping excitation switch can be done through electrical united commission of generator set. Short-circuiting terminals locally or tripping at internal outlet is an option. 3.5.4.2.2.2 Current and voltage signals to protection panel can be examined and determined through generator starting test. 3.5.4.3 Inspection for internal wire connection of device. 3.6 Individual test and total static characteristic test 3.6.1 Measurement for internal insulation of device. For excitation transformer, DC and AC busbar, the insulation must be measured prior to live test. Next step will not be allowed until all the requirements are satisfied. 3.6.2 Individual verification During commission, partial individual elements have been conducted with tests to some extent. Actual working conditions and equipment usage have been fully considered. To lower risk of test as far as possible, during shutdown for overhaul, it is recommended the following individual elements shall be examined: a) power module G05 and G15, check input and output value; b) low voltage relay K20 and K21, check motion, returned value as well as respective time; c) excitation switch Q02, measure the tripping voltage, and auxiliary contact closing conditions. d) contact inspection when excitation initializing switch is at test position. e) Contact inspection when coil intermediate relay coil is switched to test position. 3.6.3 Fan static test During static test, test prior to being put into service can be conducted for fan with fan testing parameters. Aim to check air intake of fan, and whether two sets of fans is satisfied with requirements, and whether air damper is able to function normally. 3.6.4 Light-load test Because during startup test, it is impossible to determine working conditions of excitation forcing SCR with larger conduction angle, therefore, light-load test is very important, which is regarded as the most important test of static tests. Prepare AC incoming feeder power firstly. It is recommended to adopt power being transformed directly through excitation transformer to rectifying cabinet after connecting 6KV test power supply, if there is no 6KV test power supply, 380v AC power supply can be chosen and applied to AC busbar, to simulate SCR anodic voltage, test resistor(200ohm, 2.5A sliding rheostat, just for reference, it shall be calculated according to test AC voltage in practice) can be used for simulating rotor winding. Test can be conducted on the controllable bridge of a rectifying cabinet with quiting other rectifying cabinet. After excitation is initialized by manual method, adjust control variable from -100% to +100% and record the relationship between control variable and DC output voltage, and observe DC side voltage waveform through oscillograph, and confirm trigger impulse is working normally. It shall be satisfied with design and running requirements. 3.6.5 Low excitation and over-excitation limitation test Connect output terminal of three-phase test instrument to X45-11、X45-13、X45-15 and X45-21、 X46-3、 X45-22、 X45-23 respectively, to simulate PT1 and PT2; and current output terminal to X46-1、 X46-5、X46-8、X46-10、X46-12, to simulate generator current. Set regulator to local method, and
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switch on Q02, then put excitation equipment into service, to maintain output voltage of three-phase test instrument to AC at 100V, adjust current and its phase evenly, and simulate various points of generator low excitation and over-excitation, then record current when low excitation and over-excitation limiter is triggered. And verify the function of low excitation limiter and over-excitation limiter. 3.6.6 Measurement and calibration for temperature of rectifying cabinet and excitation transformer. 3.6.6.1 Calibration for rectifying cabinet temperature: Chose thermometer with good accuracy and place it inside rectifying cabinet for 5 minutes, and determine whether current temperature is consistent with that detected by sensor when measuring temperature is being stable. This measured value can not be calibrated. 3.6.6.2 Excitation transformer temperature alarm test and tripping test Chose thermometer with good accuracy and place it inside excitation transformer for 5 minutes, and determine whether current temperature is consistent with that detected by PT100 when measuring temperature is being stable. This measured value can not be calibrated. By means of modifying parameter values respectively, realize calibration for the temperature indications of excitation transformer three-phase winding. Parameter setting, adjust temperature alarming and tripping settings as 150℃ and 160℃ respectively. Specific parameters are provided by transformer manufacturer. 3.7 No-load test ON LINE. No-load test aims to verify PID parameters of AVR manual and automatic channels, and to verify relevant parameters and limiter setting during operation. for no-load test, in accordance with manufacturer test report and requirements, the following test items shall be accomplished. For switching type test, it can be realized by means of changing relevant parameters. For regulating and limiting type test, verification can be realized through step input, however, before step input is being set, excitation current output shall be varied slowly by manual method according to actual situations to observe whether output is satisfied with requirements. After being confirmed, test can be conducted with appropriate step input setting according to requirements. Meanwhile, attention shall be paid to confirm current channel is actual control channel prior to test. Something need to be emphasized is that CMT communication state shall be on line. 3.7.1 Manual operation channel test Set manual operation preset value 2107 and lower limit 2105 to 0% and increase voltage slowly by means of manual method, and record generator no-load excitation voltage and no-load excitation current; conduct step responding test step-by-step while generator terminal voltage is within 80%-100%, and optimize PI parameters, wave recorder terminal voltage, excitation voltage, excitation current and PI output signals and etc during test process. After parameters have been regulated and optimized to best results, conduct excitation exiting command de-excitation test and direct tripping de-excitation switch de-excitation test, and record the waveforms. 3.7.2 Automatic running channel test Firstly, in accordance with generator no-load excitation voltage, set excitation forcing factor (parameter 1916), and calculate according to the following formula: (1916)=[1.35*PMG output voltage]/[0.88* no-load excitation voltage] After manual running channel has been initialized, check tracking conditions between automatic and manual modes(check parameter 12118(A_M_DIFF) <5%), and switch to automatic channel to run, and conduct step responding test step-by-step, and optimize PI parameters, wave recorder terminal
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voltage, excitation voltage, excitation current and PI output signals and etc during test process. During test, verify upper and lower limiting motions function normally. 3.7.3 Soft excitation initializing test And initialize excitation to ratings under automatic mode, and record generator voltage, excitation voltage and current waveform. 3.7.4 Switching test Perform switch between automatic operation mode and manual mode and record waveform. After commission of CH1 has been finished, copy parameters to CH2. since CH1 has been initialized, check tracking situations between the two channels, and switch over between the two channels, check wave recorder terminal voltage, excitation voltage, excitation current and status indicating signals and etc. confirm there is no impact during switching process. 3.7.5 PT disconnection test For dual-system redundant design, after PT voltage signal of CH1 has disappeared, system shall be able to switched from CH1 automatic control mode to CH2 automatic control mode, if both PT signals have disappeared, it shall be able to switched to manual channel. Under no-load operation case, pull out connected wire at PT/CT connection board successively, and verify switching control logic is normal, record wave recorder terminal voltage, excitation voltage, excitation current and such signals. 3.7.6 V/HZ limitation test Set V/HZ limitation values, under no-load operation case, firstly increase Ug to limitation point, and make 11907 begin to act, lower generator rotating speed to 80% of rated speed(step length as 2%), record Ug, f, n and such datas, verify V/HZ limiter is working normally. 3.7.7 De-excitation test for automatic running channel Perform de-excitation according to excitation exiting command and direct FCB, check and wave recorder terminal voltage, excitation voltage, excitation current and such signals, verify de-excitation process is working normally. 3.7.8 Current equalizing test Set parameters for current-equalizing test, be careful that testing current shall be less than rated current of single cabinet, observe various rectifying cabinet ammeter and parameters 10515、 10525、10535、10545, the deflection shall be less than 5%. 3.7.9 Test of switching to DC power supply Switch off small power switch F08、F09、F11 respectively, then DC power supply shall lost alarming signals and regulator works normally, and rectifying cabinet works normally. 3.7.10 Rectifying cabinet logical test Rectifying cabinet can be switched out of service by regulator interlocking the impulse when rectifying cabinet fan has fault. Alarming signal issued by single cabinet will not cause any negative influence to operation; if two cabinets have faults, the excitation forcing will be locked out; if three cabinets are experiencing from faults, the excitation regulator will exit, and 41FB switch will be tripped off at the same time. Switch off rectifying cabinet fan power supply small switch 1 to 3, to verify signal and logic correct. 3.7.11Test resumption Re-calibrate the parameter settings of the two channels carefully, and save parameters back to FLASH MEMORY(BACKUPMODE 11201)after being confirmed. Manipulation shall be realized through control panel, and remote control mode shall be switched to. 3.8 Synchronization test
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After no-load test is accomplished, the generator set shall be satisfied with synchronization requirements. Synchronization shall be performed after being controlled by synchronization device. For performance test of excitation system, most parts shall be finished in dynamic state. Those tests aim to check performance of various limitation and function modules to guarantee reliability of various unit prior to generator set being put into service. 1. synchronization curve

2. 5% step test at automatic method After synchronization, with light load being loaded, when terminal voltage reaches to rated voltage, the way is as same as no-load step test. Meanwhile, the maximum step input shall not exceed 5%,. Terminal voltage shall be lower prior to step input being applied, to make step uprising voltage being limited within range specified by operation requirements. 3. Test for switching between automatic method and constant power factor control method After excitation is initialized by automatic method, change the value assignment to switch it to constant power factor control mode, and then switch back to automatic control mode; record down waveform, and observe whether variation of voltage and current is smooth during switching process. 4. Test for switching between automatic method and constant reactive power control method After excitation is initialized by automatic method, change the value assignment to switch it to constant reactive power control mode, and then switch back to automatic control mode; record down waveform, and observe whether variation of voltage and current is smooth during switching process. 5. Verification for accuracy of PT and CT After excitation is initialized through automatic method, calibrate indicating values to being consistent with actual values according to generator voltage and current values actually measured by multi-meter. 6. 15% step test under manual method Under manual control method, it is as same as the no-load step test. Meanwhile, the maximum step input shall not exceed 15%, Terminal voltage shall be lower prior to step input being applied, to make step uprising voltage being limited within range specified by operation requirements. 7. Inspection for excitation current Ie limiter 8. Inspection for stator current Ig limiter 9. Inspection for low excitation limiter under manual method Under manual control method, actuation values for low excitation limiter shall be set in accordance with excitation current of different load. Do not cause generator set abnormal during under-excitation, otherwise, modification of setting value can be considered to finish functional examination. 10. Inspection for low excitation limiter under automatic method Under automatic control method, low excitation limiter can be determined according to under-excitation reactive power value allowed by generator set corresponding to different reactive power. During test, firstly lower generator reactive power to about zero, and then add step value for the system, by which limiter can be actuated due to reactive power of system being absorbed by generator. Attention shall be paid that generator set terminal voltage shall be guaranteed to satisfy with operation requirements during under-excitation, especially for those specified relevant protection, modification of setting value can be considered to finish functional examination.
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For test for low excitation limiter, dIfferenet points at different load shall be accomplished. Usually, one point shall be chosen at about 5%P, one at 50%P, one at 75%P, and one at 100%P. 11. PSS test To effectively suppress low frequency oscillation that may happen during operation of generator set, we have chosen PSS device. During test, with current parameters, in accordance with actual terminal voltage, appropriate step value can be applied to excitation system to cause variation on generator active power. Meanwhile, PSS device can be put into service or quitted. Observe variation of active power under different conditions. Attention shall be paid to ensure terminal voltage of generator set shall be satisfied with operation requirements during step stage. PSS test can be conducted with low excitation limiter test at the same time, Usually, one point shall be chosen at about 5%P, one at 50%P, one at 75%P, and one at 100%P. Temperature calibration for generator rotor It can be realized through corresponding relationship between resistance value and temperature. The generator rotor temperature under different load can be determined according to rotor resistance below 15℃. After temperature value under different load has bee obtained according to linear curve, compare these values with indicating values, and perform calibration. 12. Generator reactive power rejection test Generator reactive power rejection test shall be scheduled at the end of synchronization test. It aims to check voltage regulating performance when excitation device is tripped. Usually, under conditions with low active power, increase reactive power gradually. Theorically, higher reactive value means better result. However, unit terminal voltage shall not be too high during manual excitation increment. Operator shall switch off main switch of generator transformer group manually, and record waveform.

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Chapter III verification manual of generator synchronization device
1 Overview: SID-2C series microcomputer synchronization controller and SID-2SL-A microcomputer multiple function synchronization meter are selected manufactured by Shenzhen intelligent device development Co., Ltd as synchronization devices for India NAGARJUNA 2×600MW coal-firing generator set to realize automatic and manual synchronization function. 1.1 SID-2C series microcomputer synchronization controller is able to communicate with upper computer, by which it could add an important intelligent terminal for distributed control system (DCS) of power plant. Operator can get to know not only those various information at installation site of synchronization controller, but also synchronization process when they are in centralized room. 1.2 Testing and verifying units are embedded inside SID-2C series microcomputer device, by which routine test for controller, fault detection and calibration for outer circuit correctness can be conducted without other instruments and equipments. 1.3 The most important characteristics of SID-2C series microcomputer synchronization controller are automatic identification of differential frequency and synchronization, which can guarantee synchronization being realized in the minimum period with good effectiveness, and capture the first synchronization opportunity precisely. 1.4 SID-2SL-A microcomputer multiple function meters are assembled with synchronous meter and synchronization interlock relay, which is used for indicating for manual synchronization phase angle as well as manual synchronization and automatic synchronization interlock function. 2 Main function of device 2.1SID-2C primary functions 2.1.1 There are twelve channels to be used for 1-12 units power generator or power lines paralleling in a device, type and attribute of paralleling can be distinguished. 2.1.2 Setting parameters: breaker time; Allowable voltage differential; over voltage protecting value; Allowable frequency difference value; frequency control coefficient; voltage control coefficient; Allowable power angle;Incomer and busbar TV rated voltage; shift busbar TV phase angle; low voltage lock values on both sides of paralleling point; single side or both sides no-voltage operating;synchroscope funtion; Control pulse width for same frequency; breaker name . 2.1.3 The device can ensure the first zero phase differential appearing to be seized while differential paralleling (between generator and busbar or two synchronous lines.) and make paralleling without impacting. 2.1.4 The device can make a fast paralleling of generators through the way it can leads frequency differential and voltage differential into the Allowable range according to the theory of fuzzy control. 2.1.5 When paralleling will begin at once only if the power angle and the voltage difference are less than the allowable values when paralleling between synchronous lines, otherwise , there must be a wait and signal, whether it was differential frequency or identical frequency can be distinguished by the device automatically. 2.1.6 The device can make self-test when running timely and automatically, it can also alarm and display if error. 2.1.7 Alarming when TV open-circuit and locking the operation of synchronizing and non-voltage
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closing. 2.1.8 An acceleration control instruction can be given automatically when frequency is identical during the process of paralleling of generators in order to cancel the identical frequency condition. Paralleling of anti-power will be never appeared surely if necessary. 2.1.9 The device will display these data – real measuring time a breaker circuit takes when closing and the last eight real measuring values recorded in every channel after accomplishing the paralleling in order to make certain the accuracy of the time it takes when breaker closing. The time for breakers’ closing will not be recorded when it is identical frequency paralleling. 2.1.10 Communication accesses and communication agreements will be provided between the device and the host computer (RS-232, RS-485), in order to meet the requirements the device will be admitted into the DCS system. 2.1.11 The device can work even though under an awful conditions owing its methods of complete and strict insulation ways on electromagnet and photo electricity; 2.1.12 AC or DC can be as power supply of the device and the device can adapt itself to 48V—220V AC or DC power supply automatically; 2.1.13 Checking and testing can be made directly without any other apparatus because the module demanded is already in the device; 2.1.14 One side or both sides no-voltage close breaker can be accomplished according to the instructions from the host computer;or both sides no-voltage close breaker from operating the front panel switch.. 2.1.15 To be used as a intelligent synchroscope. 2.2SID-2SL-A primary functions 2.2.1 Sync channel both sides voltage phase angle instruction with analogue and digital mode. 2.2.2 There are 12 sync compelling relays in SID-2SL-A, each relay can set lockout angle alone. When external inputs difference frequency or same frequency paralleling signals, the selected sync compelling relay will automatically set a sync lockout angle value with the corresponding nature of paralleling. 2.2.3 The input TV’s voltage can be phase voltage、 line voltage or 220V. If there is an inherent phase angle between two sides, the system side TV’s voltage phase angle of each sync channel can be modified alone. 2.2.4 Each sync channel can be set allowable voltage deviation and allowable frequency deviation alone. When the difference value of voltage or frequency exceed the permissible value, the compelling relay will automatically lock the closing circuit. 2.2.5 Support non-voltage close in one/two sides. When meeting the specification, the compelling relay will be closed continuously, without needing other circuit breaker relieves it. 2.2.6There are quadruplex lockouts for voltage deviation, frequency deviation, phase displacement and power angle to ensure ultra-safe manual or automatic sync operation. But SID-2SL-A is not a synchronous device. It is incapable of catching zero phase angle to close breaker in paralleling of difference frequency. 3.Overhaul period
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Normally, major overhaul shall be performed every 48 months; minor overhaul for every 6 months. 4 Test for device 4.1 Self-test 4.1.1 A test module is supplied in the device of SID-2CM for testing and checking, which can handed all kinds of signals to the socket of JK2, JK3 and JK4 through the JK5 located on the rear of the device. These are four plugs in the connection line. They are JK2 with fourteen pins, JK3 with 26 pins, JK4 with 19 pins, JK5 with 55 pins. Not only should these plugs be connected but two power lines with 220V AC should be connected to JK7 socket and JK1 socket respectively when testing. In order to simulate that the device is power off, there may be a switch with the line of JK1 socket in series and the 220V AC power supply from JK7 socket is controlled by the switch at the right bottom of the front panel. 4.1.2 TV voltage values on both ends of incomer and busbar can be adjusted with the potentials of Vs and VG at right bottom of the panel. Whether the adjusting values shown on the display related to voltage is accordance with values measured in practice or not can also be checked with potentials of Vs and VG. 4.1.3 Twelve digits turn-code switch on the top of the test module panel can be used to simulate the synchronous switch at locale and check whether there is correct, such as no paralleling points or more than two paralleling points appear simultaneously. The device switch of TV voltage on the left can be used to make certain whether there is line voltage or phase voltage of TV voltage on busbar and incomer. 4.1.4 The keys of ‘remote reset’ and ‘auxiliary contact’ on the top of the test module are used to check whether the device can receive reset instruction from remoteness and what situation the breaker auxiliary contact is, the key of auxiliary contact can measure the breaker closing time and confirm the breaker is on the state. The state of decreasing voltage, increasing voltage, decelerating speed, accelerating speed, lock, alarm and close lock relay can be display with the seven indicator lights in an order from left to right. It means running when the relevant light is on. 4.1.5 The frequency of generator can be changed by pressing “▲”or“▼”when the generator signal source be preset to ‘inner’ during testing of the device. However, it can’t be adjusted when the signal source of ‘inner’ is from busbar. 4.2 Verification for automatic quasi-synchronization device 4.2.1 Test with voltage applied: apply voltage on automatic quasi-synchronization device, it shall be passed through self-check with “device status” being indicated normally; check the accuracy of software version and program checksum, and the indicating of clock shall be correct, otherwise, the time shall be reset by changing the passwords. All the operating key shall be in good conditions. 4.2.2 Verification for functions: apply power to automatic quasi synchronization device. 4.2.3 Examination for analog-to-digital convention: sampling for analogue shall be accuracy. Dismantle the cables of outer generator voltage, system voltage, switching-on circuit, startup circuit, alarming circuit installed at terminal block. And input rated voltage to device, and record sampling values. The error shall not exceed 5% of rated value. 4.2.4 Verification for digital value of automatic quasi-synchronization device: function of outlet shall be protected during verification, and indicating lamp shall be read correct. All alarming devices are working normally without faults. 4.2.5 Examination for input function of setting value:check and ensure functions of input of setting value as well as solidification are normal. 4.2.6 Commission: setting value shall be verified one by one according to setting value list. The regulated value of automatic quasi-synchronization device shall be consistent with setting value checklist.
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4.2.7 Preparation prior to commission: Dismantle the cables of outer generator voltage, system voltage, switching-on circuit, startup circuit, alarming circuit installed at terminal block. And connect simulated generator voltage and system voltage into corresponding circuit. And short-circuit testing points for commissioning, and then switch on the circuit and connect a signal lamp into it 4.2.8 Apply power to device: close the power supply switch, and status of device shall be shown as normal. 4.2.9 Examination for setting values: check whether those parameters are correct. Re-input those parameters if they are incorrect. 4.2.10 Frequency regulating section: the fixed system voltage is defined as 100V, 50Hz; and fixed generator voltage is designed as 100V; short-circuit the startup contact, and regulate generator frequency; when generator frequency is lower than that of system, the device shall output speed-up impulse, and the speed-up lamp is on; when generator frequency is higher than that of system, the device will emit speed-down impulse, and the speed-down lamp will be on. 4.2.11 Voltage regulating section: Frequency regulating section: the fixed system voltage is defined as 100V, 50Hz; and fixed generator frequency is designed as 50Hz; short-circuit the startup contact, and regulate generator device; when generator voltage is lower than that of system, the device shall output voltage-up impulse, and the voltage-up lamp is on; when generator voltage is higher than that of system, the device will emit voltage-down impulse, and the voltage-down lamp will be on. 4.2.12 Commissioning for switching-on circuit: the fixed system voltage is defined as 100V, 50Hz; short-circuit startup contacting points, and regulate voltage and frequency of generator; when differential voltage and frequency are satisfied with requirements, the device will issue commands for switching-on operation, and the synchronization switching-on indicating lamp shall be on with “successful switching on” message shown on LCD. 4.2.13 Frequency differential interlock: Frequency regulating section: the fixed system voltage is defined as 100V, 50Hz; and fixed generator voltage is designed as 100V; short-circuit the startup contacting points, and regulate generator frequency; when generator frequency is reaching to (50±ΔF)Hz respectively, the device is just able to release impulse for switching-on actuation. 4.2.14 Differential voltage interlock: system voltage is fixed as (100±ΔU)V, and generator frequency is fixed as 50Hz; short-circuit the startup contacting point, and regulate generator voltage; when voltage of generator reaches to 95V or 105V, device is just capable of sending impulse for switching-on actuation. 4.2.15 Disconnect wires used in test, and resume the connection of devices, and check correctness of wire connection. 4.2.16 Clear test report, and write down overhaul data into the repair report. 5. Inspection for circuit and transmission test 5.1 Put DTK switch to “auto” mode, and make device to simulate acceleration, deceleration, voltage-up and voltage-down. The automatic synchronization device shall be able to issue correct command, and the corresponding relay can perform actuation normally. 5.2 Put DTK switch to “manual” position, and press down acceleration, deceleration, voltage-up and voltage-down buttons, and switch on CS at the same time, the corresponding relay shall function normally. 5.3 Resume safety measures and clean up the site. 6. Operation test items and procedures On-site personnel must prepare all the safety and isolating measures according to requirements of on-site test items. Differential frequency synchronization test-it is applicable for synchronization test of generator, its
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transformer and breakers of busbar and circuit that can be conducted with differential frequency synchronization test. 6.1 Verification for TV signal of device (and TV phase-failure test) 6.1.1 Test measures 6.1.1.1 Safety measures shall be prepared to isolate test system from primary and secondary equipments of running system. 6.1.1.2 Disconnect synchronous closing circuit and other control circuit; disconnect auxiliary contact input circuit of breaker from terminal block. 6.1.2 Test procedures 6.1.2.1Two methods that are used for checking phase of TV secondary circuit at both side usually are optional: ·During phase verification for TV secondary circuit of both sides, which is realized by raising voltage from zero:switch on breaker of testing system to be synchronized, to make the side to be synchronized become as same system as system side. Start and raise voltage from zero to normal level, and check TV secondary circuit voltage at both sides of breaker to be synchronized. Various voltage value shall be satisfied with standards, and do recording (as reference for both side voltage regulated value), the result of phase verification shall be correct. If unit group to be synchronized fail to raise from zero and conduct phase verification for TV secondary circuit at both sides, charging at system side is an another option: disassemble three-phase connecting copper bar at unit group that is to be synchronized, and make safety and isolating measures, and then switch on breaker for synchronization, and charge the transformer to be synchronized with full voltage; check TV secondary circuit voltage at both sides of breaker to be synchronized, and ensure various voltage values shall be satisfied with standards, and make recording (as reference for both side voltage regulated value), the result of phase verification shall be correct. 6.1.2.2 Put switching switch DTK to “auto” position, and set it to “working state”, and observe that SID-2CM synchronous meter shall be stopped at 12, and measured values of voltage and frequency shall be indicated correct. Therefore, it proves that the TV signals of connected device are correct. Put DTK switch to “manual” position, then SID-2SL-A synchronous meter shall stop at position 12. otherwise, it proves that the TV signals connected with device are wrong, being misconnected or errors caused by incorrect rotating angle setting. And find out cause and resolve those issues before conducting test again. * Note: if monitoring function for TV three-phase lines of synchronization device have been put into service, TV phase-broken test shall be conducted. Disconnect each phase respectively, and observe and ensure alarming signals issued by device is correct. If this function has not been chosen, this item can be ignored. 6.2 False synchronization test 6.2.1Test measures 6.2.1.1 Breaker for synchronization and its isolating switch shall be at off position. And switch off the small switch of DC and AC operating and control power supply of isolating switch (to avoid misoperation of isolating switch). 6.2.1.2 Disconnect closing output circuit; resume the auxiliary contacting point and input circuit of breaker that is switched off at original terminal block. 6.2.1.3 During false synchronization test, measures shall be taken to prevent unit group being loaded automatically after breaker is closed. 6.2.1.4 Observe and record waveform with oscillograph or relay protection instruments. 6.2.2 After generator is starting, deviate rotating speed and voltage from rated value by manual
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method, and put synchronization device into service, and observe the synchronization speed at preset equalizing frequency and voltage control coefficient, and change those coefficients by several times, and repeat test mentioned above, and record test results to find out coefficients that can quickly realize qualification of frequency and voltage for synchronization conditions; meanwhile, observe and make sure that the rotating direction of synchronization meter shall be correct (clockwise when frequency to be synchronized is higher than that of system side, otherwise anti-clockwise). Issued speed-regulating impulse and voltage-regulating impulse shall be totally correct. 6.2.3 Connect synchronization closing circuit, and put synchronization device into service. The synchronization device shall be able to send switching-on impulse when conditions are met. And switch on the breaker to be synchronized correctly. In accordance with those recorded waveform, breaker shall be closed when differential phase angle at both sides of primary system( 3 waveforms are recommended: impulse-vabriating voltage, closing output points of device, and auxiliary contacting point of breaker). If it is switched on at non-zero angle position, regulating time shall be modified.
Tk Ud

Thc

Thf

oscillogram of synchronization Ud--- pulsation voltage; Tk--- closing time of breaker; Thc-- signal of closing impulse Thf-- Actuating signals of auxiliary contacting point of breaker 6.3 True synchronization test 6.3.1Test measures Analyze results of false synchronization test, and confirm that all the actuation of device are correct, then conduct true synchronization test. Check and ensure breaker to be synchronized is at off position; check and ensure closing output circuit is working normally; and various setting values of synchronization device are regulated according to normal operating method; close the isolating switch. 6.3.2 Start synchronization device in accordance with normal running procedures after startup of unit group. After synchronization devices have been put into service, synchronization shall be accomplished by devices. After synchronization, check recorded oscillograpm to determine time of actuating time of breaker and synchronization result. The recorded wavform shall be as the follows:

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Tk Ud

Thc

Thf

6.3.3 After test is finished, disconnect wires used in test and resume to normal connection state.

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Chapter IV verification manual of fault recorder of generator-transformer unit
1 Overview of device Model LBD-MGR-V8000 generator-transformer fault recording and comprehensive analyzing device manufactured by Baoding LBD electric Co., Ltd. are chosen as fault recording device for generator-transformer unit of India NAGARJUNA 2×600MW coal-firing unit. This device is mainly used for recording electric system fault or voltage at abnormal working condition and current data, as well as actuating sequence of corresponding protection and safety automatic device, by which the fault and varying process of electrical variable during abnormal running can appear again. And accomplish comprehensive analysis for data collected by fault recorder to provide proofs for fault cause determination, and analysis and valuation for actuation of protection and automatic device. 2 Technical characteristics and specifications 2.1Technical Characteristics 2.1.1 High Performance Design with Embedded Hardware Platform 2.1.2 Stabile and Efficient Design with Embedded Software Platform 2.1.3 High-speed Data Acquisition 2.1.4 Humanity Visual Self-diagnostic Warning Function 2.1.5 Independent Operation in Safe Mode 2.1.6 Transient, Steady-state Data Adopt Independent Double Channel Storage,

Transmission Technology 2.1.7 Security Storage of Large Volume Data 2.1.8 Network Function 2.1.9 Electrical Test Function
2.2 Technical Parameters 2.2.1 Maximum Sampling Frequency: 20kHz;Modular Transforming Precision: 16 bits;Resolution of Digital Event Channels: 0.05ms;The Highest Harmonic Resolution Ratio: 99 times. 2.2.2 Data Recording Mode The mode is classified into stable record and transient record, the data is marked with absolute time. 2.2.3 Steady Record It records electric parameters consecutively, such as voltage, current, active power, reactive power, frequency etc. The interval of the data can be set as 0.02s or 1s. 2.2.4 Mode of Dynamic Record Dynamic record was divided into A, B, C and D section to record consecutively. The set starts to run automatically when disturbance happen to power network, it records as follow: A segment: data before disturbance, the record time can be set as 40ms to 500ms. B segment: data after disturbance, the record time can be set as 100ms to 1000ms, the frequency can be set as 20/10/5/2kHz. C segment: data after disturbance, the record time can be set as 1s to 20s, the frequency can be set as 1/0.5 kHz. D segment: If concussion happen to the system, the record time can be set as 10 to 30 minutes,
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the sampling frequency can be set as 50/10/1Hz.。 2.2.4.2 Start Condition The first start: Start automatically and run sequentially as A-B-C segment when any start condition is satisfied. Repeat start: run repeatedly when new start conditions appears. Halt automatically when recording finishes. 2.2.5 Rated Parameters: AC voltage: Un=57.7V, 100V; 2*Un: Long time running; AC current: In=5A, 1A; 2*In: Long time running; Lasting 10s when 20 times overload; Lasting 1s when 40 times overload; High frequency signal:-10V~+10V, -5V~+5V; Non-electric parameters: sensor output such as temperature, pressure and so on; Digital:Normally open, normally closed passive dead contact. 2.2.5 Power Source: AC: 220V, accepted deviation: -20%~+10%; Frequency: 50Hz ± 0.5Hz, accepted deviation: -5%~+5%; DC: 220V or 110V, accepted deviation: -20%~+10% 2.2.6 Start Mode: It includes analog start, digital start and manual start mode. 2.2.7 Warning Signal It includes power down warning signal, record start signal, error-warning signal. The signal output while providing relay connection, which can be connected to center signal circuit. 2.2.8 The set has perfect function of data analyzing, error distance-measurement adopts multiple algorithms to calculate synthetically and reach high precision of 2 percent error of metallic earth. 2.2.9 Realizing many timing modes including GPS module timing, impulse timing, serial port timing. Sampling synchronously all the net is realized through GPS satellite synchronous clocking, while record data with absolute time standard made the remote dynamic recorder realized data analyze synchronously. 2.2.10 Communication The set provides Ethernet port with standard TCP/IP protocol and adopt IEC 870-5-103 communicate protocol. The recorder can share data when connected to local MIS net and realize remote control through connecting Ethernet card to MIS net. It completes the function of data transfer, remote display, setting modification, manual start. 2.2.11 Work Environment Temperature: -5°C~+45°C Relative humidity: ≤90 % 3 Overhaul period and items 3.1 Overhaul period Overhaul shall be performed after this device has been put into service for one year, thereafter, minor overhaul shall be carried out every 2 to 3 years; major overhaul shall be performed every six years. 3.1 Overhaul items 4 standard items of minor overhaul
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4.1 inspection for power supply 4.2 calibration for scale 4.3 examination for setting values 4.4 examination for sampling values 4.5 examination for component completeness 4.6 measurement for circuit insulation 5 standard items of major overhaul 5.1 inspection and cleaning for outer parts 5.2 test for accuracy of channel measurement 5.3 test for channel startup 4 Overhaul procedures and technical standards 4.1 Outer inspection and cleaning 4.1.1 Check whether connection of various analogue or digital value is loose. Fasten those screws if necessary. 4.1.2 Clean and check front-end processor and printer and so on. Install printer and its cable and power cord, and place printing paper; and check whether it is OK after power is on. 4.1.3 Front-end processor shall be in standby state, press “TAB” key repeatedly, and move selecting box to “setting input”, and then press “Enter” to verify whether setting value is correct. 4.1.4 Press down key “TEST”, and start device and record waveform, and print report and waveform for analysis. All the functions shall be in normal conditions. 4.2 Test for accuracy of channel measurement 4.2.1 Shield for startup of analogue 4.2.2 Apply three-phase voltage, and apply current after current circuit is in series 4.2.3 After entering adjusting function, and then select “verification” key and press enter key. Now measured analog values of various channels will be shown on the screen. The error of measured voltage shall be less than 1%, and error of measured current shall be less than 1%. 4.3 Test for channel startup 4.3.1 Test for upper limit startup with steady state value Check one channel and set a value for it, and set values of other channels as “0”. Startup with steady state value at upper limit: when excitation value is set as “0”, then the applied voltage shall be 55V or 1A current; increase excitation volume slowly until device startup, then observe the accuracy of startup. Startup with analogue at lower limit: when excitation volume is set as “56V or 1.3A”, the applied voltage shall be 50V, current as 1A; slowly decrease the excitation volume until device startup, then observe accuracy of startup. After test is done, set setting value to “0”. The accuracy of startup shall not be more than 2% during test above. 4.3.2 Startup test with sudden change Check channel and set a value for it, and set values of other channels as “0”. Check sudden change during startup, and the setting value is usually defined as: voltage as 5V, current as 0.8A. Then apply excitation volume beyond setting values suddenly, to actuate the device, and observe the accuracy. After test is done, set setting value to “0”. The accuracy of startup shall not be more than 2% during test above. 4.3.3 Sequence and other startup test
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Positive-sequence over-voltage: setting value as 63V, apply balancing excitation to three-phase voltage, from 55V with excitation volume slowly until startup, and then observe accuracy of startup. Positive-sequence under-voltage: setting value as 50V, apply balancing excitation to three-phase voltage, from 55V with excitation volume slowly until startup, and then observe accuracy of startup. Negative-sequence current state volume: setting value as 0.5A, apply negative-sequence excitation volume to three-phase current, from 0.3A with excitation volume slowly until startup, and then observe accuracy of startup. Negative-sequence voltage state volume: setting value as 5V apply negative-sequence excitation volume to three-phase voltage, from 3V with excitation volume slowly until startup, and then observe accuracy of startup. Differential frequency startup: set value as 0.5Hz, apply 50Hz voltage 50V to phase A voltage, and then modify frequency of excitation volume until startup, then observe accuracy of startup. Startup of rate-of-change of frequency: set value as 0.1Hz/s, then apply 50Hz voltage 50V to phase A voltage, and then modify frequency of excitation volume until startup, then observe accuracy of startup. 4.3.4 Startup of digital value channel Short-circuit digital value channel to be measured, and observe that “switch startup” lamp shall be on. after pressing “reset 0”, test various digital value channel accordingly. 4.4 Regulation for setting value After test is done, all the setting values shall be regulated and be printed and filed. Because the variation of current or voltage is relative high during fault happening, particular conditions of various areas are different. Therefore, modify setting values appropriately according to actual situations of operating method to avoid wrong actuation being triggered during normal operation. Note: rated values mean the secondary value of PT/CT. 4.5 Inspection for Synchronous clock 4.5.1 Check synchronous clock calibration function that is realized by outer synchronous clock signals (GPS). The device shall be able to receive signals from outer synchronous clock and realize automatic clock calibration. 4.5.2 When synchronous clock signals have been interrupted, the clock error shall not be more than 5S in 24 hours. 4.6 Test for reliability of recorded data 4.6.1 After waveform recording for device has been launched, the working power supply of device shall be cut off. The device shall be able to kept reliable waveform data that are recorded in 2 seconds before power supply is cut off. 4.6.2 After waveform recording is launched, recorded information shall not be lost or erased by operating any switch or key on device. 4.6.3 Check and ensure that no device crash will happen in no event. 4.7 Examination for remote transmission function 4.7.1 After waveform recording is launched, device shall be able to transmit recorded data actively or passively by automatic or manual method. 4.7.2 Remotely launch device to record waveform, and device shall be able to realize remote waveform recording. 4.7.3 It can realize remote modification for setting values and relevant system parameters. 4.7.4 During transmission of data, if channel is interrupted, device shall be able to deal with those issues correspondingly.
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4.7.5 Check the time consumed by device for transmitting a 3S basic wave record file, and make sure it is satisfied with requirement of device design. 4.8 Resume measures, and check and ensure the device is in normal conditions.

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Part III inspection manual for instruments
Chapter I Inspection and technical manual for electrical measuring transducer
1 Content and scope The housing of S3(T) electrical measuring transducer is made from high-strength fire retardant materials, with advanced and reliable circuit design for software and hardware, with special thick-membrane circuit, hyper-linearisation sensor and high precise resistors and capacitors. It features with stable performance, high-precision measuring, good linearization, good temperature characteristics and lighting-proof function. S3(T) series three-phase active transducer measures the three-phase three-way active power by two meters method. S3(T) series three-phase reactive transducer adopts two-meter phase-crossing method to determine three-phase three-way reactive power (these transducers are also called balanced three-phase reactive transducer). This standard have defined overhaul period and items of electric measuring transducer, as well as overhaul working sequence and treatment for inspection results. 2 Overhaul period and inspection items 2.1 Overhaul period Periodical inspection for transducer shall be performed in coordination with overhaul of those secondary equipments connected with the transducer. Main measuring and important transducer shall be examined every year. The transducers used for other aspects shall be inspected at least once every three years. 2.2 Overhaul items a. cleaning and inspection for transducer circuit. b. determination of transducer c. reassemble the transducer, and resume safety measures. d. cleanse working site. 3 Preparations for overhaul 3.1 All tools and materials and as such shall be prepared 3.2 Check standard instrument, meters and measuring devices; 3.3 Conduct work order procedures for commencement. 4 Overhaul sequences of transducer 4.1 Cleaning and inspection for transducer circuit Wire connection terminals and secondary wire shall be free of carbonization trace, and screws shall be fastened firmly. Labels of wire connection terminals shall be complete and correct. Letters printed on cable labels shall be clear and correct. The wire connection terminal and secondary wire shall be clean and free of dust gathering. 4.2 Determination of transducer (comparative measuring method) Comparative measurement (hereafter as “comparison method”) is based on those meters or devices which range is equal to or approximate to that of transducer to be determined. Therefore two measured results shall be compared with each other for test purpose. And this method is applicable for determination of the exact
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transducer. Periodic inspection items Visual examination, determination of insulation resistance, measurement of basic error, and determination of outputted ripple content. 4.2.1 Visual examination The following marks and symbols shall be printed on the housing of transducer: a. Manufacturer name or brand, product model and name, serial number or date, class level, category of parameters to be measured and line numbers, higher and lower nominal values of parameters to be measured, output current(voltage) and range of output load, test voltage and auxiliary power supply parameters. b. Marks of usage shall be clearly printed on the wire connection terminals. c. There shall be no crack or apparent damage on the housing; screws shall be complete; there shall be no sound from inner side when it is being shaken d. Check sealing conditions. 4.2.2 Measurement of insulation resistance The measured insulation resistance of all circuit connected together(input circuit and additional circuit) to reference grounding point shall not be less than 5MΩ. This measurement shall be conducted after 500V DC voltage being applied for 1 minute. 4.2.3 Determination of basic error During verification of transducer, measured data and calculated data shall be regulated prior to being filled into the verification certificate. Transducer shall be determined according to regulated data. Procedures to determine basic error by comparison method Wire connection for test: Connect with outer auxiliary power supply for transducer to be calibrated; AC current input circuit of transducer to be calibrated shall be connected in series into AC current output circuit of standard device`; AC voltage input circuit of transducer to be calibrated shall be connected in series into AC voltage output circuit of standard device`; DC output circuit of transducer to be calibrated shall be connected to DI/AI terminal of calibrator, then start power switch of standard device, and conduct pre-treatment for transducer. During pre-treatment, besides applied auxiliary power voltage, nominal values to be measured shall be applied. every test points shall be applied with excitation to make the readings of standard meter be equal to nominal values. And Ix, the readings of output circuit DC meter shall be recorded. Formula for basic error calculation(Ix-Is)/IF×100% Is, IF—standard value of output current; nominal value of output current mA When transducer is working under these comparative conditions, the error of any point between higher nominal value and lower nominal value of output signal shall not exceed the value limit of basic error. Determination of input standard value and output standard value Select N values with equalizing distance between higher and lower nominal values to be measured as the input standard values, including the two value limits; Select N values with equalizing distance between higher and lower nominal values of output values as the output standard values, including the two value limits; For voltage and current transducer, N shall not be less than 6, and 6 is recommended. For frequency and phase transducer, N shall not be less than 9, and 9 or 11 is recommended. For power transducer, besides those principles mentioned above, two more test points shall be
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added. The two points shall be equal to the central value of forward and reverse outpt scope respectively. Determination for three-phase active power transducer Diagram of three-phase active power transducer is shown as figure a, figure b is corresponding vector diagram (a)connection diagram (b)vector diagram

procedures of basic error determination Measure basic error of transducer during forward work, for dual-directional transducer, basic error during reverse running shall be determined. a. With conditions as cosψ=1(ψ=0°), apply every forward points with nominal voltage, and modify current to make the readings of standard device be equal to its nominal value. And then record Ix, the reading of output circuit DC milliampere meter b. Under conditions as cosψ=0.5(inductivityψ=60°), for those forward test points applied with 50% of nominal voltage or below, current shall be modified to the readings of standard device is equal to its nominal value. And then record Iy, the reading of output circuit DC milliampere meter; c. With conditions as cosψ=0.5(capacitanceψ=+300°), for those forward test points applied with 50% of nominal voltage or below, current shall be modified to the readings of standard device is equal to its nominal value. And then record Iz, the reading of output circuit DC milliampere meter; Note: for transducer that are not going to be used under capacitance load condition, item c can be ignored. Component test For transducer for which basic error and variation have exceed the limits, component shall be tested and regulated separately, and then measure basic error and variation against till it is being qualified. Component test shall be conducted during transducer is in forward running state. And the current circuit of other component not to be checked shall be cut off. Test error for component test shall not be regarded as basic error of transducer to be determined, which is only considered as principle for valuating results of component commissioning) Error of component test shall not exceed the half of basic error limit of transducer to be determined. For dual-directional transducer, basic error during reverse running shall be measured. There are two methods for test, either of them is acceptable. a. In accordance with forward working error verification, however, cosψ shall be modified (phase angle ψ plus or deduct by 180°), and make the forward-directional testing point to become reverse-directional testing points. b. In accordance with forward working error verification, however, direction of various phase shall be modified, and make the forward-directional testing points to become into reverse-directional testing points.
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Verification of three-phase reactive power transducer Diagram of balanced three-phase reactive power transducer is shown as figure a, and figure b is corresponding vector diagram. (a)wire connection diagram (b)vector diagram

Figure 10. diagram and vector diagram of balanced three-phase reactive power transducer Measure the basic error of transducer during forward running, for those dual-directional transducer, basic error shall be determined during reverse running. a. With conditions as sinψ=1(ψ=90°), apply every forward points with nominal voltage, and modify current to make the readings of standard device be equal to its nominal value. And then record Ix, the reading of output circuit DC milliampere meter b. Under conditions as sinψ=0.5(inductivityψ=60°), for those forward test points applied with 50% of nominal voltage as 100V or below, current shall be modified to the readings of standard device is equal to its nominal value. And then record Iy, the reading of output circuit DC milliampere meter; c. With conditions as sinψ=0.5(capacitanceψ=-60°), repeat procedure b; And then record Iz, the reading of output circuit DC milliampere meter; Note: for transducer that are not going to be used under capacitance load condition, item c can be ignored; For dual-directional reactive power transducer, basic error of transducer shall be measured during reverse running. The test method is as same as that of active power transducer. 4.2.4 Determination of output ripple content All factors shall be kept under reference conditions, and excitation shal be applied to transducer to make output be equal to the higher nominal value. The output ripple content shall be measured directly by calibration instruments. 4.3 Reassemble the transducer. Various connection of transducer shall be correct, reliable, smooth and satisfied with installation drawings. And resume all the safety measures. 4.4 Cleaning of working site Check omission, and clean up working site, clarify and explain overhaul, conduct work order procedure. 5.Checkup and filing for transducer 5.1 Review for verification record and certificate of transducer Measured data and calculated data, before being filled into the verification certificate, shall be trimmed and rounded. Spacing basic error shall be rounded according to 1/10 of class, and rounding spacing of output value and absolute error shall be equal to or approximate to CAF×10-3(C as rating index of transducer; AF is defined as reference value of transducer ) . Transducer shall be determined according to rounding data. Stick certificate of compliance on the qualified transducer,
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and note with effective date as well as verifier. Present certificate of verification, and submit to personnel with certificate of transducer verification for review. The verification items shall be filled completely and clearly. International units shall be adopted. 5.2 Quality acceptance. Fill out the quality acceptance sheet.

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Chapter II overhaul manual for electrical measurement digital meter
1.Main content and applicable scope N2 series digital meter is made up of high-strength fire retardant materials with international standard dimension and appearance. It features with new style, advanced and reliable circuit design, special circuit chip, hyper-linear sensor and precise resistor and capacitor component. It is highlighted with red LED digitron with reliable performance, high precision, good linearization and lower power consumption. This standard has defined overhaul period, items and overhaul working sequence of digital meter, as well as treatment for verification result. 2.Overhual period and verification items 2.1 Overhaul period Verification period for digital meter shall be performed in coordination with overhaul of primary equipments connected with this digital meter. For digital meter of main measuring points, verification shall be conducted every year; and for digital meter that are used for other purpose, the verification period shall not be more than two years. 2.2 Overhaul items 2.2.1 cleaning and inspection for digital meter circuit; 2.2.2 verification of digital meter 2.2.3 reassembly of digital meter, resumption of safety measures. 2.2.4 cleaning of working site 3.Preparations before major overhaul 3.1 Preparations for tools and materials as required 3.2 Examination for standard instrument, meters and verifying devices 3.3 Conduct work order procedures for commencement 4.Overhaul sequence for digital meter 4.1 Cleaning and inspection for digital meter circuit Wire connection terminals and secondary wire shall be free of carbonization trace, and screws shall be fastened firmly. Labels of wire connection terminals shall be complete and correct. Letters printed on cable labels shall be clear and correct. The wire connection terminal and secondary wire shall be clean and free of dust gathering. 4.2 Verification of digital meter periodic verification items 4.2.1 Visual examination Instrument name, manufacturer name or brand, model, serial number, rating and other information for correct usage shall be printed on the housing of digital meter; there shall be no crack or obvious injury on housing. 4.2.2 Measurement of insulation resistance Within the allowable temperature range, relative humidity no more than 80%, insulation resistance of
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input terminal and auxiliary power terminal to housing( or to grounded terminal connected with housing), and of input terminal to auxiliary power terminal, shall not be less than 5MΩ. This measurement shall be conducted after 500V DC voltage being applied for 1 minute. 4.2.3 Determination of basic error(comparison method) Procedures to determine basic error by comparison method Wire connection for test: connect with outer auxiliary power supply for digital meter to be calibrated; AC current input circuit of digital meter to be calibrated shall be connected in series into AC current output circuit of standard device`; AC voltage input circuit of digital meter to be calibrated shall be connected in series into AC voltage output circuit of standard device`; then start power switch of standard device, and condut pre-treatment for transducer. Calibration shall be carried out after indications raising up to about 80% of full range under rated load for preheating 15min ~30min. Checking procedures for digital current and voltage meter are listed as the follows: a. Select testing frequency as 50Hz. b. Usually, 10 testing points will be selected, however the number shall not be less than 5. all the points shall be picked evenly. c. Read indications shown on meters to be checked and that on standard meters. d. Formula for calculating error of ammeter: γ = ( I x − I N ) / I m in the formula: I x ——indications to be checked meter to be checked

I m ——upper limit of measuring scope of

I N ——standard indications U m ——upper limit of measuring scope of

formula for calculating voltmeter error: γ = (U x − IU N ) / IU m in formula: U x ——indications to be checked meter to be checked U N ——standard indications Checking procedures for AC digital power meter are listed as follows: a. Select checking frequency as 50Hz. b. Selection of checking points. When cos (sinφ)=1, select voltage as Un, select current as 0, 50%In, 80%In, and 100%In; when cosφ(sinφ)=0. 5(L) and cosφ(sinφ)=0. 5(c), select voltage 20%In, as Un,current as In; Un is defined as rated voltage, In as rated current. c. Read indications shown on meters to be checked and that on standard meters. d. formula for calculating error: γ = [( X − X 0 ) / X n ] × 100% in formula: X ——indications of power meter to be checked

X 0 ——standard value

X n ——rated power。
Procedures of digital power frequency meter are specified as the follows: a. At rated voltage, adjust frequency source to make frequency being up to 45 Hz, 48 Hz, 49 Hz, 49.5 Hz, 50 Hz, 50.5 HZ, 51 Hz, 52 HZ and 55 Hz in a stable manner, and then record readings from standard frequency meter. b. Formula used for error calculation: γ = [( f x − f 0 ) / f in formula: f checked f
0 N N

] × 100%
x

——reference value of meter to be checked f

——indications to be

——standard indications
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Error of actual measurement for various points shall not be more than the percent of rating index of meter to be checked. 4.2.4 Test for discriminability Standard device provides output value to make meter to be checked display a value, meanwhile, record value X1 which is outputted from standard device, trim the output of standard device and make reading of meter to be checked change a number at the end digit, then record value X2 which is outputted from standard device. The difference between two indications, is regarded as discriminability of meter to be checked. Discriminability shall not be more than CAm10-2 C---- rating index of meter to be checked Am---- upper limit of meter range to be checked(reference value) 4.3 Reassemble the digital meter, and resume wire connection of digital meter circuit. The wire connection shall be correct, reliable, smooth. It shall be satisfied with installation drawings. Safety measures shall be resumed. 4.4 Cleaning of working site Check for omission, and clean up working site, clarify and explain overhaul, conduct work order procedure. 5.Verification and filing for digital meter 5.1 Original record of digital meter examination shall be reviewed by personnel with certificate of digital meter verification. The verification items shall be filled completely and clearly. International units shall be adopted. It shall be kept at least one examination period. Effective digits of verified data shall be more than accuracy of meter to be checked by one. data shall be trimmed in accordance with even number rounding rules. Qualification shall be determined according to rounded data. Stick certificate of compliance on the qualified digital meter, and note with effective date as well as verifier. 5.2 Quality acceptance. Fill out the quality acceptance sheet.

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Chapter III Overhaul manual for multi-function watt-hour meter
1.Main content and applicable scope DDSSD/DTSD2818 multi-function watt-hour meter is compatible with IEC60653 standards. The main characteristic includes: digital measuring chip, no physical adjusting elements, signal digital calculation, digital filtering, digital error correction, digital calibration, insensitive to temperature, and excellent smoother and rectifier elements. Varying augment measurement and multi-section digital compensation are integrated into this product, which can realize accurate high over-load multiple (0.5 class 12 multiple) watt-hour power calculation. Power capacity at lowest load conditions also can be recorded. Voltage, current, power factor and power can be measured precisely. Basic function includes active bi-directional, reactive four-quadrant four-rate data-processing unit, meanwhile, the max required capacity indicating of four-rate and other relevant functions can be realized. Impulse indicating of watt-hour capacity can be realized by two highlighted LEDs. Total active capacity is indicating at the left side, and total reactive capacity at right side(lighting time is equal to width outputted by check impulse). Data of can be read from meter through RS485 interface or load control terminal of infra-red communication port or other data terminal device. Therefore, watt-hour charging system of capacity can be made up; communication protocols are satisfied with standards of multi-function watt-hour meter. And data can be displayed on LCD in form of IEC 62056-61 OBIS codes. After measurement, phase A, B and C transient active/reactive power and apparent power as well as voltage, current, power factor, phase angle and frequency can be displayed in real-time manner. And those indications can be read out from RS485 or infra-red port. This standard has defined overhaul period, items and overhaul sequence of electronic multi-function watt-hour meter, as well as treatment and verification for results. 2.Overhaul period and verification items 2.1 Overhaul period Verification period for watt-hour meter shall be performed in coordination with overhaul of primary equipments connected with this digital meter as far as possible. Usually, the period shall be five years. 2.2 Overhaul items 2.2.1 Cleaning and inspection for watt-hour meter circuit; 2.2.2 Verification of watt-hour meter; 2.2.3 Reassembly of watt-hour meter, resumption of safety measures. 2.2.4 Cleaning of working site 3. Preparations before major overhaul 3.1 Preparations for tools and materials as required; 3.2 Examination for standard instrument, meters and verifying devices 3.3 Conduct work order procedures for commencement 4. Overhaul sequence for watt-hour meter 4.1 Cleaning and inspection for watt-hour meter circuit Wire connection terminals and secondary wire shall be free of carbonization trace, and screws shall be fastened firmly. Labels of wire connection terminals shall be complete and correct. Letters printed on cable labels shall be clear and correct. The wire connection terminal and secondary wire shall be clean and free of dust gathering.

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4.2 Verification of digital meter Periodic verification items Measurement of insulation resistance; visual inspection and examination with power applied; start and end test; determination of basic error of watt-hour capacity; Determination of watt-hour measuring standard deflection valuation; calibration of indications on meter 4.2.1 Measurement of insulation resistance Within the allowable temperature range, relative humidity no more than 80%, insulation resistance of input terminal and auxiliary power terminal to housing( or to grounded terminal connected with housing), and of input terminal to auxiliary power terminal, shall not be less than 100MΩ. This measurement shall be conducted after 1000V DC voltage being applied for 1 minute. 4.2.2 Visual examination and inspection with power Instrument name, manufacturer name or brand, model, serial number, rating, impulse constant, rated voltage, basic current and rated max current and such labels shall be printed on the housing of digital meter; label shall be complete form and clear; measures to prevent unauthorized access or meter being open shall be available; there shall be no crack or obvious injury on housing. Check whether the indicating number is clear and correct; whether keys are in normal conditions and function normally. After visual inspection and examination with power are passed, connect watt-hour meter with verification device. AC current input circuit of watt-hour meter to be calibrated shall be connected in series into AC current output circuit of standard device`; AC voltage input circuit of watt-hour meter to be calibrated shall be connected in series into AC voltage output circuit of standard device`; impulse output terminal of watt-hour meter to be calibrated shall be connected with impulse collecting terminal of calibration device. Then the following test shall be conducted. 4.2.3 Startup, creep and halt of test Under rated voltage, rated frequency and cosψ=1.0(active power) or sinψ=1.0(reactive power) conditions, when load current raises to 0.1% of basic current meter, there shall be impulse output from watt-hour meter. Apply rated voltage to voltage circuit. When there is no current in current circuit, and within 10 times of one impulse produced by starting current, there shall be no more than one impulse being outputted. 4.2.4 Determination of basic error of watt-hour capacity measurement It shall be determined through standard meter method, i.e. comparing the watt-hour value measured by standard meter and meter to be checked respectively with each other, to determine calibration method of relative error of meter to be calibrated. When watt-hour capacity of meter to be checked has reached the preheating times with power, load point verification required by the following table shall be performed. Load power to be regulated for three-phase active and reactive watt-hour meter under balanced load cosψ=0.5 cosψ=1.0 cosψ=0.8 Conne sinψ=0.5 sinψ=1.0 (capacitance) ction Classification (inductivity) method load current

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Conne cted through PT/CT or Univer al PT/CT

Active watt-hour meter Reactive watt-hour meter

0.1Ib,0.5Ib,Ib Imax

0.2Ib,0.5Ib Ib,Imax

0.2Ib,0.5Ib Ib,Imax

Note: when Imax≥4Ib, (Imax-4Ib)/2 testing points shall be added. cosψ=0.8(capacitance), during periodic erification, adopt. cosψ=0.866(capacitance) is allowed to

Load power to be regulated for three-phase active and reactive watt-hour meter under unbalanced load Power factor of each group of elements cosψ=1.0 cosψ=0.5(inductivity) Load current 0.1Ib 0.2Ib Ib(Imax) Ib(Imax)

Note: verification for load points included in brackets shall be determined in accordance with practice requirements Under each load, at least two measurements shall be performed, and select average as measured result. If calculated relative error is equal to 80%--120% of basic error of this meter, two more measurements shall be performed, and select these two measured values and previous average as measured result. Relative error shall not be more than percentage of rating index of meter to be checked. 4.2.5 Determination of standard deviation estimate of watt-hour measurement. Under rated voltage, 50Hz and basic current, for cosψ=1.0 、cosψ=0.5(inductivity)two load points shall be conducted with at least 5 relative error measurements. And standard deviation estimate S(%) shall be calculated according to the following formula, and it shall not be more than 1/5 of accuracy rating.

S=

1 n ( X i − X )2 ∑ n i =1

n—number of repeating measurement

n≥5

X i —No. n measured relative error(%) X —average of error measured each time(%)
4.2.6 Check constant With impulse-counting method, under conditions with rated voltage, rated max current and power factor as 1.0, when indicator is changed by 0.1 kWh, the output impulse counting number N shall be equal to calculated value 0.1C(C is defined as watt-hour constant), only error of one impulse shall be allowed. 4.3 Reassembly for watt-hour meter and resumption of safety measures
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Reassemble the watt-hour meter, and resume wire connection of digital meter circuit. The wire connection shall be correct, reliable, smooth. It shall be satisfied with installation drawings. Safety measures shall be resumed. 4.4 Cleaning of working site Check for omission, and clean up working site, clarify and explain overhaul, conduct work order procedure. 5. Verification and filing for watt-hour meter 5.1 Verifying record of watt-hour meter, and review of verification certificate Measured data and calculated data shall be rounded prior to being filled into the verification certificate. Qualified watt-hour meter shall be sealed with lead sealing and stuck with certificate of compliance, and noted with effective dat and verifier. Present certificate of erification and submit to personnel with certificate of watt-hour meter verification for review. The verification items shall be filled completely and clearly. International units shall be adopted. 5.2 Quality acceptance. Fill out the quality acceptance sheet

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Part IV electrical equipment overhaul manual for electrostatic precipitator
1 Structural principle of electrostatic precipitator India NAGARJUNA 2×600MW coal-firing boiler electrostatic precipitator consists of two chambers, and each chamber is made up of five electric fields. Type TM-II electrostatic controller manufactured by Hangzhou Tianming environmental engineering Co., Ltd isi chosen as electrical control equipment of electrostatic precipitator Working principles of electrostatic precipitator: when fume is passing through the electrostatic precipitator, particles in air flow mixture will be charged by cathode corona. With function of electric field, charged particles will be driven to and gathering on the dust-collecting pole. Therefore, dust accumulated on dust-collecting pole will be removed by vibrating device, by which dust can be separated from air flow. 2 Technical specifications 2.1 Characteristics of TM-II electrostatic dust-collecting controller Advanced 32-bit ARM9 micro-controller and DSP digital signal processor are selected by core control logic, with powerful processing capacity, fast responding speed, high accuracy and reliability. Auto frequency detecting function. It is applicable for any AC working frequency output voltage Fast and accurate overflash capture function according to voltage and current variation in electric field. Best treatment based on operation conditions. Six running methods. best operation method can be chosen in accordance with operation conditions. 10 group of programmable IO and six auxiliary input are provided, by which different peripheral equipments can be controlled, and DCS monitoring electric field can be connected. And flexibility of engineering application has been improved. Rapping sequence can be realized through configuring time sequence control module cascaded by 10 time sequence control modules, by which users can control rapping sequence accurately. Energy-saving control. Energy consumed by high-voltage field, and rapping and heating parts will be saved significantly. Human-friendly user equipment interface. Startup and shutdown of equipment, parameter display/setting and switch of operating method, alarming/fault display, can be realized by RTM (remote terminal monitor). And on-site level monitoring can be realized. Factory level monitoring also can be realized through industrial Ethernet network. And maintenance cost can be reduced. Complete detecting function. It can conduct real-time detection for current, voltage, turbidity, level and transformer oil temperature and such signals. Perfect fault protection and alarm function. Control unit is able to respond to and deal with faults timely; fault or alarm information can be displayed on monitoring equipment in time. Real-time clock. It can display/modify current year, month, day and hour, minute and second.
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Power-off memory function. Defined parameters can be stored after power-off and without being set again. Parameter can be uploaded or downloaded easily. Data that are modified at local RTM can be saved to local RTM or current monitored controller, also can be saved into other controller. 2.2 Function of type TM-II electrostatic dust-collecting controller After 380V industrial power has been treated by SCR through HV power supply device, it will be sent into the transformer for voltage boosting, and then be delivered to precipitator as power supply after being rectified through rectifier. TM-ii controller will detect relevant signals, and begin to control SCR conduction angle according to requirements, and regulate power supply for precipitator. Additionally, in accordance with settings, TM-II controller will realize control of rapping motor, heating device and such LV equipments. 2.3 Rectifying transformer

Z Z D J --- 1.6 A / 72 KV --combinated style HV rectiformer single-phase copper coils structure self-cooling with oil immersion (KV)

HW outdoor type assembled rated rectifying voltage

rated rectifying current(A) 3 Electrostatic precipitator overhaul period and overhaul items 3.1 Overhaul period 3.1.1 Major and minor overhaul periods of electrostatic precipitator are as same as those of boiler proper. 3.1.2 Usually, major overhaul period is 4 years. 3.1.3 Minor overhaul shall be performed every 6 months. 3.2 Overhaul items for electrical equipments of electrostatic precipitator 3.2.1 Minor overhaul items 3.2.1.1 HV power supply system: a、 Cleaning and inspection for rectiformer top terminal box, damper resistor, insulator, leading wire and so on. b、 Cleaning and inspection for HV isolating switch and operating mechanism. c、 Cleaning and inspection for HV leading wire in rectiformer top rapping chamber, supporting insulator, rapping magnetic axis, cathodic magnetic bottle and so on. d、 Cleaning and inspection for various elements in HV control cabinet. Control cabinet shall be measured with 500V megger, and insulation resistance shall be more than 2MΩ(auto voltage controller shall be unplugged) e、 Cleaning and inspection for elements and components in server terminal control cabinet (21m) and client terminal console (dust-collecting control room)
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f、 Measurement for insulation resistance of HV circuit (including leading wire, isolating switch, insulating bushing, cathodic big framework). g、 Elimination of defects happening during operation. 3.2.1.2 LV electrical equipment a、 Cleaning and inspection for various elements in dust-collecting MCC cabinet. b、 Cleaning and inspection for power cabinet. c、 Cleaning and inspection for various elements in electromagnetic rapping control cabinet. d、 Cleaning and inspection for various elements in rapping control cabinet. e、 Cleaning and inspection for various elements in electrical heating control cabinet. f、 Cleaning and inspection for dust-collecting on-site level terminal box, overhaul power box, lighting terminal box, dust hopper heating terminal box, insulated cabinet heating terminal box, electromagnetic rapping terminal box and so on. g、 Elimination of defects happening during operation. 3.2.2 Overhaul items 3.2.2.1 HV supply system: a、 Disassembly of silica rectiformer b、 Overhaul of electric field HV isolating switch and operating mechanism. c、 Cleaning and inspection and test for HV leading wire in rectiformer top rapping chamber, supporting insulator, rapping magnetic axis, cathodic magnetic bushing and so on d、 Cleaning and inspection and test for rectiformer insulating bushing in electric field HV isolating switch box, leading wire, damper resistor, supporting insulator, cathodic magnetic bushing in incubator and other heating elements. e、 Overhaul of HV sampling and measuring circuit. f、 Cleaning and inspection for HV control cabinet, elements in automatic voltage controller. Calibration of gauge(which shall be sent to electrical department for calibration). Cleaning and inspection for elements of precipitator IPC system(server terminal cabinet, client terminal console) 3.2.2.2 LV electrical equipment a、 Cleaning and inspection for various elements in dust-collecting MCC cabinet. b、 Cleaning and inspection for power cabinet. c、 Cleaning and inspection for various elements in electromagnetic rapping control cabinet. d、 Cleaning and inspection for various elements in rapping control cabinet. e、 Cleaning and inspection for various elements in electrical heating control cabinet. f、 Cleaning and inspection for dust-collecting on-site level terminal box, overhaul power box, lighting terminal box, dust hopper heating terminal box, insulated cabinet heating terminal box, electromagnetic rapping terminal box and so on. g、 Elimination of defects happening during operation. h、 Test for grounding resistance. 4 Procedures and standards of equipment overhaul 4.1 HV power supply system 4.1.1 For disassembly and overhaul of silicon rectiformer, please refer to table 1. Table 1. Overhaul requirement and quality standard for silicon rectifying transformer Technical Overhaul requirements and quality standards procedures

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Visual inspection and treatment

1) Cleanse the housing of transformer 2) Check whether HV and LV leading wire is loose, and whether porcelain bottle is broken, and whether oil is leaking from junction part. 3) Check whether gasket is sealed tightly, and whether wall plate is crushed, damaged or have oil leakage problem. 4) Check whether glass of upper oil gauge of oil conservator is broken, and whether oil is leaking from there, and whether moist absorber is being damp.

preparations for core lifting

1) Voltage withstand test for transformer oil (it shall be more than or equal to 40KV/2.5cm) prior to core lifting as well as chemical analysis shall be conducted. If test failed, oil filter machine shall be used for filtering purpose. 2) check whether electric hoist, steel cable and lift hook and such tools for core lifting are in good conditions. Included angle between steel cable and lifting object shall not be more than 30 degree. Before bigger cover is being removed, to avoid oil leakage from conservatory, transformer oil shall be discharged through oil outlet until oil level is below the transformer top cover. Discharged oil shall be stored in clean barrel and sealed tightly. The storage time shall be as short as possible to avoid insulation being lowered due to dampness. 3) Fire-fighting measures shall be available for overhaul site. All personnel shall be allocated with duty clearly.

Core lifting

1) Inspection for core lifting shall be performed under dry and clean environment. 2) Inspection for core lifting shall be performed in fine days. Wind-proof and dust-proof measures shall be taken. When core lifting is performed in winter, ambient temperature shall not be less than 0℃. Transformer core temperature shall not be lower than ambient air temperature. Otherwise, transformer shall be heated and make core temperature is above ambient air temperature by 10℃ to avoid being damp. 4)Time of core being placed in outdoor air: for dry weather(relative humidity shall not be more than 65%), 24 hours is allowable. 5)Disconnect leading wire at both HV and LV side of transformer. take care those porcelain bottles. 6)Disconnect grounding wire and secondary wire connection. 7)Unscrew upper cover screws, and keep them appropriately. 8)During core lifting, special personnel shall be responsible for guiding the process. Four corners shall be sent personnel for supervision. When trail lifting is passed, then begin to lift. Lifting process must be steady. Insulation must not be collided. Place core gently and slowly on the sleeper when it has been separated from proper.

Inspection of core

1) Carefully check core surface and compressing conditions. It shall be clean and free of oil filth and partial overheating. 2) Check upper and lower yoke iron of core, and the supporting frame shall be intact.

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3) Check and ensure various screws are fastened tightly without any looseness. 4) Through screw shall be fastened firmly, and insulation resistance measured by 2500V megger between through bolt and iron yoke(grounding clip shall be dismantled) shall be more than 5MΩ Inspection of coil 1) Check coil fastening conditions and insulation conditions. Those loose sections shall be fixed and bound. HV and LV coil shall be free of crack, discoloration, getting crisp and such insulation injury trace. For sections getting heated severely, cause shall be figured out, and partial insulation treatment shall be enhanced. 2) Insulation of leading-out wire shall be in good conditions. Welding joint must not be overheated. Junction part shall be fastened firmly. Wooden supporting frame shall be intact. 3) Foreign matter accumulated on coil surface shall be cleaned with white cloth or plastic forth. Inspection for HV silicon stack 1) The surface of HV silicon stack shall be clean, and free of discoloration; all the nuggets shall be free of tip-off and false welding. Conjunction shall be fastened firmly without overheating. 2) Use 2500V megger to check unidirectional conductivity of HV silicon stack, or use rheostat to test forward and reverse resistance. O for forward direction, and reverse direction resistance shall be more than 1000MΩ 3)Check filter condenser and ensure the surface is clean and free of foreign matters. Conduct charging and discharging test with 2500V megger. Charging and discharging performance of all the capacitors shall be good. There shall be no puncture and breakage Detection of feedback resistor 1) Surface of various measuring and feedback resistors shall be smooth and clean. Junction shall be firmly fastened. Nugget surface shall be smooth without false welding and burrs. 2) Measure various resistor resistance(voltage sampling resistance, current sampling resistance). The actual values shall be satisfied with rated values, and error shall be less than ±5%. Detection of temperature gas liquid level relay Inspection for grounding device 1) Performance of temperature, pressure, level relay shall be reliable. 2) Movable part shall be flexible and free of jamming and adhension. 3) Returning of contacts shall be reliable. And contacting resistance shall be less than 0.2Ω. 1) The housing of rectifying transformer shall be well grounded. Grounding of positive electrode shall be absolutely reliable. Grounding resistance of transformer and electric field shall be less than 1Ω. 2) Measurement for grounding resistance shall be conducted every 2-3 major overhaul period. If grounding resistance fails to meet standard requirements, it shall be reinstalled or replaced. 1) After overhaul of suspended core is accomplished, and no problem is

Reassembly

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found, reassembly can be performed after being accepted and confirmed by supervisors. 2) Oil-resisting and acid-resisting rubber cushion shall be placed along with flange. Measures shall be taken to avoid disalignment of rubber cushion. 3) Only same core is allowed to reassemble. 4) When core is in place, personnel shall be ready to puncture crowbar into the flange. And place down the core when oil screw hole is located. During fastening of screws of bigger cover, it shall be repeated many times. Usually, the rubber cushion shall be compressed by 1/3 of original thickness. Inspection for damper resistance 1) Sootblown for damper resistor shall be performed. It shall be free of crack found in visual examination. The resistance wire shall be free of electric-discharging and burnt trace. The junction part shall be fastened firmly. 2) Measure resistance of damper resistor, which shall be consistent with design value. Reassembly after major overhaul or minor overhaul, the following work shall be performed after cleaning and inspection: 1) The resistance of rectifying transformer LV side to ground shall be more than 300MΩ when being measured with 1000V megger. The insulation resistance between LV side and HV side shall be more than 300MΩ 2)Insulation resistance of rectifying transformer HV side to ground shall be more than 1000MΩ when being measured by 2500V megger. 4.1.2 Overhaul of electric field HV isolating switch and operating mechanism:

Test

a、 Visual examination: check various supporting insulating components, and clean them up. Treatment and replacement shall be performed if injury, crack or electric discharging trace is found. b、 Inspection for mechanism, and quality standards: operating of switch shall be flexible and convenient. Actuation shall be accurate and in place. The indicating of outer switch position shall be correct. Moving contact and static contact of switch shall be contacted well. Corresponding interlock auxiliary contacting point shall be accurate and in position, and contact shall be reliable. c、 The insulation resistance measured by 2500V megohom meter shall be more than 100MΩ 4.1.3 Overhaul of electric field HV isolating switch box, insulating bushing in incubator and such as. a 、 Dust accumulated on insulation bushing, cathodic magnetic bushing, leading wire and supporting insulating component surface shall be cleaned with cloth. Check whether bushing and supporting insulating component is injuried or cracked or with electric discharging trace. Check and ensure bushing heating elements are in good conditions. b、Clean dust gathering on damper resistor, and check whether resistance wire is burnt by electric discharging or broken. c、Check and confirm that HV junction is well connected without looseness. d、 The insulation resistance measured by 2500V megohom meter shall be more than 100MΩ. 4.1.4 Overhaul for HV leading wire in rectiformer top rapping chamber, supporting insulator, rapping magnetic axis, cathodic magnetic bushing and so on.
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a、Clean dust gathering on HV leading wire, insulating clip that lifts HV leading wire, supporting insulator, rapping magnetic axis and cathodic magnetic bushing surface. b、Check and confirm that all the insulating components shall be free of injury, crack and electric discharge. Check and ensure HV soft-connecting contact is well contacted without looseness or electric discharging trace. c、The insulation resistance measured by 2500V megohom meter shall be more than 100MΩ. 4.1.5 Overhaul of HV sampling and measuring circuit a、 Clean dust accumulated in rectifying transformer top terminal box; and check whether sampling circuit is being screened well. b、Check and ensure sampling resistance and measuring resistance are equal to design values. When deviation value is exceeding 10%, cause shall be found out, replacement shall be performed. Then calibrate meters again. Check whether over-voltage protection elements are in good conditions. 4.1.6 Cleaning and inspection for HV control cabinet and elements inside auto voltage controller. Calibration for gauge. Cleaning and inspection for elements in dust-collecting IPC system (server terminal cabinet, client terminal console and so on). a、 Dust gathering on terminal block and plugging components in HV control cabinet, server terminal cabinet and client terminal console shall be cleaned up. b、 Check wiring of control circuit. Secondary wire connection shall be satisfied with drawings. Check and confirm the labels are correct and clear. c、 Check and ensure commutator, buttons, fuses, indicating lamp and such as are fixed firmly without looseness. Switch and button shall be flexible. And contacting is in position. d、 Terminal blocks shall be fastened, and wire-connecting screws of and various elements and components shall be well contacted. g、 Check appearance and quality of various components of auto voltage regulator. The welding quality shall be good. All the chips shall be compressed tightly. Various elements and components shall be clean and tidy. h、 Check appearance quality of various plugging elements of precipitator IPC system(server terminal cabinet, client terminal console and so on). The welding quality shall be good. All the chips shall be compressed tightly. Various elements and components shall be clean and tidy. e、 Calibration for gauge: calibrate primary and secondary voltage meter and current meter. It is required that indication of gauge shall be correct. Error shall be within the required range. f、 Resistance measured by universal meter between SCR control pole G and cathode K shall be about scores of ohms. Resistance of fast-fuse shall be zero. g、 Check and ensure SCR cooling fan is moving flexibly without jamming. 4.1.7 Examination and commission of voltage auto regulator After installation of equipment is accomplished, commissioning shall be performed in accordance with the following procedures. 1) Confirm QF1, SA and KM1 are off, and secondary side of rectifying transformer is free of load of electric field. 2) In according with diagram, check various connected wire with multi-meter, and confirm all the connections are correct. 3) Set address for each TM-II controller through DIP switch. The address shall not be repeated. And then turn :NETWOEK” button on TM-II control panel to right side to realize communication with RS-484.
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4) Disconnect connection between power A1 and No.1, No.13 port of TM-II controller. And disconnect connection between transformer T2 secondary side and ports No.10 and 22 of TM-II controller. 5) Switch on QF1, and then switch on SA. Use multi-meter to measure whether output of A1 is equal to 24V, and whether transformer T2 secondary side output is 5V. if those output is not satisfied with requirements, then check A1 or T2 for fault. 6) Disconnect SA, and then QF1. Re-connect wire between A1 and port No.1 and No.13, as well as connection between transformer T2 secondary side and ports No.10 and 22 of TM-II controller. 7) Firstly, switch on QF1, and then close SA, to make TM-II controller being powered. If “POWER” indicating lamp on control panel is on, it means the power of TM-II controller is supplied normally. 8) Confirm communication of RS-485. Check whether “RTM” indicating lamp on each controller panel in RS-484 network is on. If on, it means that communication of this controller is normal. Check node list of RTM (it is shown in starting picture), if node numbers of controllers in list are equal to the actual numbers, it means communication between RTM and all the controllers is OK. 9) Choose target to be monitored for RTM. The procedures are shown as follows: “node list” picture (starting picture) →press or move cursor to where the controller node to be monitored in the node list→ press ? key, then the controller node will be set as monitored target by RTM. And then enter into corresponding menu system of this controller node.(for usage of RTM, please refer to “TM_RTM manual”) 10) Download preset parameters stored in RTM to TM-II controller. The procedures are shown as follows: “main menu” page →select “save parameter” option →enter “parameter save/upload/download” page →perform “resume default parameter configuration” operation. 11) Check whether TM-ii controller is able to start or halt normally. Press down “run/stop” button on RTM, if indicating lamp “RUN” on TM-II controller panel is on, it means that TM-II stars successfully. After a moment, press down “RUN/STOP” button on RTM again, if indicating lamp “RUN” on TM-II controller panel is off, it means that TM-II has exited operation normally. 12) Check whether SCR triggering system is normal. Press down “RUN/STOP” button on RTM, after a while, indicating lamps “T/R1 ON” and “T/R2 ON” will flash instantaneously. And indications will be shown on secondary voltage meter and secondary current meter, which means SCR triggering system is normal and HV power-supplying device is running normally. After about 15 seconds, indicating lamp “ALARM” on controller panel will be on, and lamps “T/R1 ON”and“T/R2 ON” will be off, and SCR triggering system will halt. Open-circuit fault will be shown on RTM display. Delete those faults by manual method and press down “RUN/STOP” button on RTM again, the controller will restart the triggering system of SCR. 4.2 LV electrical equipment 4.2.1 MCC Dust-collecting MCC a、 Clean and check switches, contactors and such elements and components in cabinet. b、 Fasten electrical joint screws of various switches, contactors and terminal blocks. c、 Check and ensure all the switches and contactors shall be able to move freely and well connected without jamming. d、 Insulation resistance to ground of busbar, which is measured by 500V~1000V megohm

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meter, shall not be less than 1MΩ. 4.2.2 Electromagnetic rapping control cabinet a、 Clean and check various plug-in elements and components in cabinet b、 Check the appearance of various plug-in elements, and they shall be free of burnt trace. The welding quality shall be satisfied with requirements. All be chips shall be plugged firmly. c、 Check phase-controlling board, and bolts of column and row board SCR cathode and anode. And fasten them again if they are found loose. d、 Check and ensure that small switches of various row selection and column selection are flexible with good contacting, and protection setting values are satisfied with requirements. e、 Check whether terminals of various switches and terminal blocks are loose or disconnected. And fasten them again to make it being contacted well. f、 Check the wiring of control circuit. Secondary wiring shall be satisfied with requirements of drawings. g、 Check rapping coil, and measure and confirm that forward and reverse resistance of isolating diode is free of short-circuit and grounding phenomenon. Forward resistance shall be scores of ohms, and reverse resistance shall be more than scores of kilo-ohms. 4.2.3 Rapping control cabinet a、Clean and check minor busbar, switches and various plug-in components in cabinet. b、Fasten electrical coupling screws of various switches, contactors and terminal blocks. And make them being contacted well. e、 Check and ensure operation of various switches is flexible and contacted well. And protection setting values shall be satisfied with requirements. f、 Check and ensure all the contactors shall be able to move freely and well connected without jamming. g、 Check the wiring of control circuit. Secondary wiring shall be satisfied with requirements of drawings. h、 Insulation resistance to ground of busbar, which is measured by 500V~1000V megohm meter, shall not be less than 1MΩ 4.2.4 Overhaul of electric heating control cabinet a、Clean and check minor busbar, switches and various plug-in components in cabinet. b、Fasten electrical coupling screws of various switches, contactors and terminal blocks. And make them being contacted well. c、Check and ensure operation of various switches is flexible and contacted well. And protection setting values shall be satisfied with requirements. d、Check and ensure all the contactors shall be able to move freely and well connected without jamming. e、Check the wiring of control circuit. Secondary wiring shall be satisfied with requirements of drawings. f、 Insulation resistance to ground of busbar, which is measured by 500V~1000V megohm meter, shall not be less than 1MΩ. 4.2.5 Cleaning and inspection for on-site level terminal box, lighting terminal box, ash hopper heating terminal box, incubator heating terminal box and electromagnetic rapping terminal box of electrostatic precipitator a、 Clean dust gathering in terminal box
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b、 Fasten screws of terminal block, and make them being contacted well. 4.2.6 Measure of grounding resistance Various LV control cabinet shall be grounded reliably. The grounding resistance shall be less than 2Ω. 5 Test for cold-state, electric field characteristic without smoke 5.1 Test purpose To check overhaul result, performance and control characteristic of electric field and HV power-supplying device, cold-state characteristic test must be conducted after whole overhaul of electrostatic precipitator has been finished. 5.2 Preparations prior to test 5.2.1 Dummy load test for HV control cabinet a、 Check and ensure wiring connection inside HV control cabinet is well arranged. Disconnect wire between main circuit and silicon rectifying transformer primary side, and connect tow 220V 100W incandescent lamp in series as dummy load. b、 Primary sampling signal shall be suspended temporarily. Otherwise, the circuit will be open due to tripping during voltage boosting. c、 Contact operator to call back relevant work order. And take safety measures before power is on. d、 After power is on, start the equipment, and boost voltage by manual manners, and the buld shall become bright gradually, and primary voltage reaches to 380V. and SCR shall be full open. Then decrease voltage, and repeat these steps several times. Because no feedback signal is existing, and then no primary current, secondary voltage and current will be shown. This test only can be used for roughly check whether the control cabinet is normal basically. e、 If bulb becomes bright suddenly or be always off since startup, it means there is fault in control system or main circuit section. The further examination shall be conducted. f、 Resume primary voltage sampling signals, and conduct power-cutting procedures, and resume those safety measures. g、 For test of other electric field, conduct procedures as same as those mentioned above. 5.2.2 Test of various LV control cabinet with power (no.1 electrostatic precipitator) 5.2.2.1 Energizing test for electrostatic heating cabinet a、Set all the switches on cabinet panel to “stop” position, and electric heating control cabinet begins to supply power. b、 Switch on air switches and all the breakers in cabinet. c、 Check those control temperature settings at TM-II shall be satisfied with those following values: heating settings for incubator: 120℃ as upper limit, 100℃ as lower limit, 80℃ as alarming temperature; heating settings for ash hopper: 100℃ as upper limit, 90℃ as lower limit, 80℃ as alarming temperature; d、 Check whether elements is being heated abnormally after power is on for half of a day. e、 Set the heating switch on cabinet panel to “manual” position, and check whehter electric heater is working normally, and check whether indications of TM-II is OK. f、 Set the heating switch on cabinet panel to “auto” position, and check whether electric heater is working normally, and check whether indications of TM-II is OK g、 Further examination shall be performed if abnormality has bee found. h、 Shutdown: Set the heating switch on cabinet panel to “stop” position, and switch off air switches in cabinet.
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5.2.2.2 Energizing test for rapping control cabinet a、This work must be coordinated with motor group and dust-collecting group. b、Set all the switches on cabinet panel to “stop” position, and rapping control cabinet begins to supply power. c、Switch on air switches and all the breakers in cabinet. d、Check with DDJX micro-terminal to determine whether time of rapping procedure is satisfied with requirements. e、Check whether elements is being heated abnormally after power is on for half of a day. f、 Firstly, set local rapping switch to “off” position, and then set rapping switch on cabinet panel to “manual” position. And then check whether rotating direction of rapping motor is correct. And check indicating status of DDJX micro-terminal is normal. h、 Set rapping switch on cabinet panel to “auto” position, and check whether rapping motor is working according to program, and check whether indicating status shown on TM-II is normal. i、 Further examination shall be performed if abnormality has bee found. j、 Shutdown: Set all the switches on cabinet panel to “stop” position, and switch off air switches in cabinet. 5.2.2.3 Energizing test for electromagnetic rapping control cabinet. a、 Use multi-meter to measure whether resistance between various rows and columns is satisfied with requirements. b、 Disconnect row and column selection breakers. And switch on mains of rapping cabinet as well as power supply of rapping control. c、 Connect row and column selection breakers. And let rapping device work for several hours under matrix mode. d、 Check and ensure rapping height and rapping period are satisfied with requirements. Otherwise, it shall be regulated. e、 Shutdown: switch off mains of rapping cabinet as well as power supply of rapping control. 5.3 Conditions required by test a、 Insulation test for rectifying transformer, insulation test for HV circuit, voltage withstanding test for transformer oil, insulation test for electric field, insulation test for various LV control cabinet and grouding resistance test shall be passed. b、 100KV HV electrostatic meter shall be prepared. c、 All the manholes shall be closed. d、 Put incubator and ash hopper heating device into service, remove moisture around incubator and insulator surface to avoid creeping caused by dampness. And then put rapping, dust-delivering and dust-unloading devices into service. 5.4 Cold-state test 5.4.1 Use single equipment to boost voltage for each electric field a、HV electrostatic meter shall be installed in the isolating switch cabinet at proper top. And monitoring personnel shall take care of themselves. After all the safety conditions are confirmed, the HV control cabinet begins to supply power. Press down “run/stop” button on RTM, and the whole device is entering into running status. Indications of primary current, secondary voltage and secondary current meter shall vary with status of electric field of electrostatic precipitator. Therefore, access to display screen by screen, and set to manual position, and the manual current limit is set as 0%.
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b、 During cold-state test , special personnel shall be responsible for monitoring the HV silicon rectifying transformer. c、 Increase the setting values by manual manner, to make it raise to rated current value or voltage standard value. d、 Calibration for meters shall be performed after operation becomes stable, adjust current limit by manual method. When secondary voltage shown on HV electrostatic meter reaches 40KV, adjust RP1 at sampling board in HV control cabinet to make indications of meters be equal to those of electrostatic meters. As the same, calibration shall be performed at 50KV, 60KV, and 70KV. e、 Adjust indications of secondary current I2: : measure 122 voltage to ground with multi-meter DC voltage range, then I2=U122/R9,and then regulate RP3 at sampling board, to make I2 be equal to actual value. g、Adjust indicated values shown on LCD: adjust RP2, make indication of U2 be approximate to meter indications of U2 ; adjust RP3, and make indication of I2 be approximate to meter indications of I2 ; adjust RP4 and make indication of I1 be approximate to meter indications of I1; adjust RP5 and make indication of U1 be approximate to meter indications of U1; h 、Volt-ampere characteristic test: firstly, observe corona starting voltage, and then by manual voltage-boosting method, record primary and secondary voltage, primary and secondary current value as well as SCR conduction angle point by point with an interval as 5KV. And then decrease voltage by manual method to do record point by point in reverse direction. Verify raising and declining values of each point, they shall be consistent with each other basically. i、Conduct same test for other electric fields. j、After test is done, lower down voltage of electric field, and trip off power supply switch of HV control cabinet. Safety measures shall be available. k、 Problems found during test shall be treated after test is done. 5.4.2 Power supplied by same two rectifying equipment connected in parallel for one electric field. a、 For power supply for single unit, when current reaches rated value, but voltage fails to reach rated value, two equipments shall be employed for voltage boosting for one electric field. However, during this operation, the electric field shall be free of fault when voltage of single power-supplying equipment is boosted. b、 The capacity of two rectifying equipments shall be the same. Tapping of rectifying transformer primary side shall be consistent with each other. Phase of input power supplies shall be identical. Spark power-supplying method shall be employed. c、 The realization of output terminals of rectifying transformer that are mounted at the proper top in parallel is relatively difficult. However, it shall be safe and reliable and being fastened tightly. During parallel, the damper resistor output terminal of various rectifying transformer shall be connected in parallel. When current of two equipments enter into the electric field through a damper resistor, the current will be increased by about 100%; if energizing time is too long, the damper resistor may be damaged. d、 Start the two control cabinet instantaneously, and conduct voltage boosting for two equipments instantaneously and slowly with same raising speed. Boost current and voltage to rated values by manual method. During voltage boosting, every 5KV shall be regarded as a point, and record primary and secondary voltage and current value, and then prepare volt-ampere characteristic curve. e、 If abnormal case is found during voltage boosting, press down reset button timely to reset the two equipments instantaneously. And figure out causes and resolve these cases timely.
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f、 During cold-state test , special personnel shall be responsible for monitoring the HV silicon rectifying transformer. g、 After test is done, lower down voltage of electric field, and trip off power supply switch of HV control cabinet. Make safety measures available. h、 Conduct same test for other electric fields. i、 After shutdown, check joints of main circuit cables, and check whether there is overheating existing at large current contacting section such as transformer due to poor contact.. if found, it shall be resolved timely. 6 Commissioning of IPC system 6.1 Start console of main host, and ensure main circuit is working normally. If abnormality is found, check and repair main circuit fault. Start various lower computers and ensure they can work normally. 6.2 Start on-site IPC, and run IPC system software, and then input correct user name and password, and log in IPC system. 6.3 Check in turn, and confirm that communication between IPC system and lower computers is normal. If abnormality is found, check whether communication port is well connected and in correct position. 6.4 Switch various working windows, and check whether those indications of data are correct are satisfied with data of lower computers. 6.5 Check whether working setting parameters of various operation forms are correct, and check whether IPC system is able to send new parameters to low computers for control.. 6.6 Check and test other functions of IPC system in turn, and check correctness of them. 6.7 Connect to printer, and check whether it can print TR operation form or other pictures correctly. For common faults of power-supplying control equipment of electrostatic precipitator, please refer to table 2. Table 2. treatment for common faults of power-supplying control equipment of electrostatic precipitator No. Symptom of fault Causes Treatments 1 Primary voltage is low, and primary current is large; secondary voltage is approximate to zero, and secondary current is very large. 1) Short-circuit happens between corona pole and dust-collecting pole due to too much dust accumulated in ash hopper 2) Wire of corona pole is broken. 3) Short-circuit to ground caused by dew or dust gathering in insulating bushing or due to HV insulator injury. 1) Clean out soot in ash hopper 2) Deal with broken wire after shutdown 3) Replace for damaged insulator, and clean out soot, and put heating service into service or increase heating temperature. 4 ) Remove foreign

4) Short-circuit caused by metallic matters located between different poles. matters after shutdown 2 Primary voltage is low, and primary current is approximate to zero; secondary voltage is very high, and secondary current is equal to zero

1)Isolating switch is not in position 1 ) Place HV isolating during closing operation switch to where electric 2)Damper resistor at electric field field is located. 2)Damper resistor top has been burnt out.

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3

Primary voltage is normal, and primary current is relative low; secondary voltage is relative low, and secondary current is decreased apparently.

1) Rapping period of corona pole is 1)Adjust rapping period too long, which cause severe dust accumulation, and corona is closed. 2)Inadequate corona pole rapping force 3) Corona pole rapping device fault 4)Concentration of soot at electric field is too high, and reverse coronary happens(secondary current is too high or too low) 2 ) Treat and improve rapping system 3)Deal with faults 4 ) Contact and adjust combustion and pulverization system. 5)Change type of coal

4

5

Primary voltage, primary current, secondary voltage and secondary current are relative low and accompanied with vibration and noise from rectifying transformer which is increasing following the increment of current. With high oil temperature. Primary voltage and current is normal; secondary current is relative high with unstable oscillation, and secondary voltage is relative low accompanied with overflash Primary voltage and current, and secondary voltage is normal; secondary current is equal to zero

1 ) Triggering circuit of SCR is 1) Resolve triggering circuit asymmetric. 2)There is a break in SCR circuit fault. 2) Replace for damaged

3)If transformer oil temperature is SCR not too high, voltage regulator shall 3 ) Repair and adjust be regulated again. voltage regulator automatic

1)Wire of corona pole is broken, 1 ) Treat those broken but there is no break caused by this. And spacing between poles becomes smaller than ever. 2)Foreign matters mixed in pole plate and wires of electric field being damp due to heating device fault wires after shutdown; regulate pole spacing after shutdown 2) Remove foreign matters after shutdown repair heating device

3)Insulators at corona pole top are 3)Cleanse insulators and

6

1 ) Secondary current sampling 1) Check screened cable signals are short-circuited to end screened line. 2 ) Check and treat 2)Measuring circuit of secondary measuring circuit current meter is short0-circuited 3 ) Check and repair 3 ) Pointer of secondary current gauges meter has been stuck. 1)Electric discharge happens at 1 ) Treat electric

7

Too frequent electric field overflash, and lower efficiency of dust collecting

isolating switch, damper resistor discharging parts and supporting insulator. 2)Regulate spark rate 2)Spark rate of control cabinet has 3) Regulate rapping period not been regulated appropriately 4 ) Check 3)Inappropriate rapping period of abnormal
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and

treat electric

front electric field discharging points in 4 ) Abnormal electric discharging electric field after shutdown 5 ) Adjust working points are existing in electric field. 5 ) Variation of smoke working conditions is violent. 8 conditions of boiler flue gas

shall be Indications of gauge is 1 ) Air leakage of precipitator is Overhaul performed after shutdown normal, however serious efficiency of 2)Air-conducting plate at inlet, and dust-collecting is relative air distributing plate have fell apart. poor 3)Flow limiting plate at ash hopper have fell off. And flue gas is short-circuited

9

Operation voltage is Low, and current is low too, or severe overflash, tripping of HV control cabinet happens along with increment of voltage

1 ) Smoke temperature is lower 1 than dew point, which will decrease insulation of HV components, and severe overflash will happen under low voltage conditions.

) Regulate

boiler

combustion or halt operation of electric field 2 ) Repair those faulted rapping devices

2)Rapping fails to work. Too much 3) Repair insulating sealed more dust is gathering on pole plate or incubator plate and wires, which will lower the 4)Treat and regulate fault break-down voltage limit. points with partial smaller 3)Spacing between different poles of electric field become smaller partially 4) Positioning pin of dust-collecting pole plate is displaced due to being broken. spacing after shutdown

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