Tan Delta
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Tan Delta
Tan Delta is an effective tool in determining the insulation condition of power cables using a VLF-TD System Tan Delta measures the resistive component of a cable system; a perfect cable is all capacitance and has no resistance. The resistive component is caused by voids in the insulation electrical trees water trees etc. The resistive element causes the voltage not to lead the current by !"# $something less% This is difference in angle $less than &# % is the loss angle. The tangent of this loss angle is the Tan Delta ' or the tangent of the loss angle. tan delta testing is usally carried out to chec( the healthiness of insulation.so this testing is usally carried out in cb ct bushings etc for all these e)uipements one standard value will be there for brea(ers this value will be "."""*+ if any devation in this value we have to suspect about it insulation healthyness. ,deally an insulation $be it across a cable or a electrical switch gear% should be of infinite resistance. That is ideally if voltage is applied across insulation no current should pass through $considering resistive current only%. -ow there is another aspect of an insulation. .n insulation is also a capacitor $two plates seperated by dielectric% and hence there must be some current $opf course ac current% that will flow if voltage is applied acroos insulation $this is capacitive current%. -ow the ration of the resistive current $which shoud ideally be /ero% and the capacitive current is called loss tangent or tan delta and is measurable. So if tan delta is measured we are actually get an idea of the resistive current through the insulation. . high tan delta indicates high resistive current and that means insulation is detoriating. tan angle is the ratio of resistance current and capacitive current ..it is used to estimate the life of insulation by comparing periodical tandelta value of the same insulation..pure insulation has only capacitive current but with the insulation deteriorationor cavity formation$may occur due ambient condition temp or cont. over current flow% resistance is added hence resistive current increase wich leads to increase in tandelta value. ,deally an insulation $be it across a cable or a electrical switch gear% should be of infinite resistance. That is ideally if voltage is applied across insulation no current should pass through $considering resistive current only%. -ow there is another aspect of an insulation. .n insulation is also a capacitor $two plates seperated by dielectric% and hence there must be some current $opf course ac current% that will flow if voltage is applied acroos insulation $this is capacitive current%.0 ,D1.L 2.3.2,T,V1 24551-T ,S .L6.7S !" D18 .91.D T9.- V:LT.81 .S 315 5-2 2,524,T V12T:5 D,.85.;.<4T D41 T: .8,-8 1FF12T 0 D1T:5,.T,:- :F ,-S4L.T,:- 2.3.2,T,V1 24551-T ,S SL,89TL7 L1SS T9.T !" D18 0 :-1 .-8L1 251.T1D <1T ,D1.L 2.3.. 24551-T 0 .<:V1 S.,D 24551-T ,S 2.LL1D T.- D1LT. .-8L1. 91-21 61 2L1.5L7 S.7 T9.T T.- D1LT. ,S the ration of the resistive current $which shoud ideally be /ero% and the capacitive current is called loss tangent or tan delta and is measurable. So if tan delta is measured we are actually get an idea of the resistive current through the insulation. . high tan delta indicates high resistive current and that means insulation is detoriating. n general for electrical component Ten delta means that the tangent value of insulating material. what is tangent value of ,;= it is nothing but the dissipation factor. what is dissipation factor= The ratio of 3ower' Voltage-.mpear $6'V.%. so finally in simple words Tan delta testing is nothing but to find out the health of insulation :5 insulating material.The test can be performed on 2ables power T5>s or any electrical component.
Tan Delta is an effective tool in determining the insulation condition of power cables using a VLF-TD System Tan Delta measures the resistive component of a cable system; a perfect cable is all capacitance and has no resistance. The resistive component is caused by voids in the insulation electrical trees water trees etc. The resistive element causes the voltage not to lead the current by !"# $something less% This is difference in angle $less than &# % is the loss angle. The tangent of this loss angle is the Tan Delta ' or the tangent of the loss angle. tan delta testing is usally carried out to chec( the healthiness of insulation.so this testing is usally carried out in cb ct bushings etc for all these e)uipements one standard value will be there for brea(ers this value will be "."""*+ if any devation in this value we have to suspect about it insulation healthyness. ,deally an insulation $be it across a cable or a electrical switch gear% should be of infinite resistance. That is ideally if voltage is applied across insulation no current should pass through $considering resistive current only%. -ow there is another aspect of an insulation. .n insulation is also a capacitor $two plates seperated by dielectric% and hence there must be some current $opf course ac current% that will flow if voltage is applied acroos insulation $this is capacitive current%. -ow the ration of the resistive current $which shoud ideally be /ero% and the capacitive current is called loss tangent or tan delta and is measurable. So if tan delta is measured we are actually get an idea of the resistive current through the insulation. . high tan delta indicates high resistive current and that means insulation is detoriating. tan angle is the ratio of resistance current and capacitive current ..it is used to estimate the life of insulation by comparing periodical tandelta value of the same insulation..pure insulation has only capacitive current but with the insulation deteriorationor cavity formation$may occur due ambient condition temp or cont. over current flow% resistance is added hence resistive current increase wich leads to increase in tandelta value. ,deally an insulation $be it across a cable or a electrical switch gear% should be of infinite resistance. That is ideally if voltage is applied across insulation no current should pass through $considering resistive current only%. -ow there is another aspect of an insulation. .n insulation is also a capacitor $two plates seperated by dielectric% and hence there must be some current $opf course ac current% that will flow if voltage is applied acroos insulation $this is capacitive current%.0 ,D1.L 2.3.2,T,V1 24551-T ,S .L6.7S !" D18 .91.D T9.- V:LT.81 .S 315 5-2 2,524,T V12T:5 D,.85.;.<4T D41 T: .8,-8 1FF12T 0 D1T:5,.T,:- :F ,-S4L.T,:- 2.3.2,T,V1 24551-T ,S SL,89TL7 L1SS T9.T !" D18 0 :-1 .-8L1 251.T1D <1T ,D1.L 2.3.. 24551-T 0 .<:V1 S.,D 24551-T ,S 2.LL1D T.- D1LT. .-8L1. 91-21 61 2L1.5L7 S.7 T9.T T.- D1LT. ,S the ration of the resistive current $which shoud ideally be /ero% and the capacitive current is called loss tangent or tan delta and is measurable. So if tan delta is measured we are actually get an idea of the resistive current through the insulation. . high tan delta indicates high resistive current and that means insulation is detoriating. n general for electrical component Ten delta means that the tangent value of insulating material. what is tangent value of ,;= it is nothing but the dissipation factor. what is dissipation factor= The ratio of 3ower' Voltage-.mpear $6'V.%. so finally in simple words Tan delta testing is nothing but to find out the health of insulation :5 insulating material.The test can be performed on 2ables power T5>s or any electrical component.
