Substation Automation using SCADA

1

SUMMER INTERNSHIP REPORT
On
Substation Automation using SCADA and
Financial Modeling of 5 MW Solar PV
Under the Guidance of

Ms. Indu Maheshwari
Dy. Director (NPTI, Faridabad)
&
Mr. Anil Vaishy
D.G.M SCADA BSES Yamuna
At

Submitted by
ANKIT SINGH
MBA – Power Management
Roll No: 16 ; Batch 2012-14
Affiliated to
MAHARSHI DAYANAND UNIVERSITY, ROHTAK
(A State University established under Haryana Act No. XXV of 1975)
2

CERTIFICATE


3

DECLARATION


I, Ankit Singh, Roll No. 16, class 2012-14 of the National Power Training Institute, Faridabad
hereby declare that the Summer Training Report entitled “Substation Automation using
SCADA and Financial Modelling of 5 megawatt Solar PV plant” is an original work and the
same has not been submitted to any other institute for the award of any other degree.

A seminar presentation of the Training Report was made on 3
rd
August 2013 and the suggestions
approved by the faculty were duly incorporated.




Presentation In charge
(Faculty)
Signature of the Candidate
(Ankit Singh)
Countersigned
Director/Principal of the Institute


4

ACKNOWLEDGEMENT

I would like to express my sincere gratitude to all the people who had been associated with me in
some way or the other and helped me avail this opportunity for my summer Internship on the
topic ““Substation Automation using SCADA and Financial Modelling of 5 MW Solar PV
plant””.

I acknowledge with gratitude and humanity my indebtedness to my Summer Internship guide
Mr. Anil Vaishy D.G.M (SCADA),BSES Yamuna for providing me excellent guidance and
motivation under whom I completed my summer internship
I would like to thank my Project In-charge Ms. Indu Maheshwari, Deputy Director, NPTI,
Faridabad for his support and guidance throughout the course of summer internship.

A special thanks to Mrs. Indu Maheswari, Dy. Director, NPTI and Dr. Rohit Verma, Dy.
Director, NPTI for their guidance throughout my summer internship.

I would like to thank Mr. S.K. Choudhary, Principal Director (NPTI), Mrs. Manju Mam,
Director, NPTI and all faculty members for arranging my internship at TERI and being a
constant source of motivation and guidance throughout the course of my internship.


Ankit Singh
Summer Interns
NPTI, Faridabad


5

TABLE OF CONTENTS
PROJECT TITLE ………………………………………………………………………………1
CERTIFICATE ......................................................................................................................2
DECLARATION ....................................................................................................................3
ACKNOWLEDGEMENT ......................................................................................................4
TABLE OF CONTENTS ........................................................................................................6
LIST OF FIGURES ................................................................................................................7
LIST OF TABLES……………………………………………………………….………………8
COMPANY PROFILE…………………………………………………………..………………9

CHAPTER 1 INTRODUCTION TO SCADA………………………………………………..13
1.1 NEED FOR SCADA………………………………………………………………15
1.2 BENEFITS OF SCADA…………………………………………………………..17

CHAPTER 2 DISTRIBUTION SUBSTATIONS……………………………………19
2.1 TYPES OF SUBSTATIONS………………………………………………………21
2.2 CLASSIFICATION OF SUBSTATIONS………………………………………...24
2.3 MAIN INSTRUMENTS USED IN DISTRIBUTION SUBSTATION………….28

CHAPTER -3 BASICS OF RTU AND SCADA APPLICATIONS………………………..43
3.1 SCADA APPLICATIONS……………………………………………………56

CHAPTER-4 FINANCIAL MODELLING OF SOLAR PV 1 MW ……………………..63
CHAPTER-5 CONCLUSION………………………………………………………………..76
CHAPTER-6 REFERENCES……………………………………………………………….77




6

LIST OF FIGURES

Figure 1 ....................................................................................................................................................... 11
Figure 2 ....................................................................................................................................................... 18
Figure 3 ....................................................................................................................................................... 19
Figure 4 ....................................................................................................................................................... 21
Figure 5 ....................................................................................................................................................... 23
Figure 6 ....................................................................................................................................................... 23
Figure 7 ....................................................................................................................................................... 23
Figure 8 ....................................................................................................................................................... 28
Figure 9 ....................................................................................................................................................... 32
Figure 10 ..................................................................................................................................................... 35
Figure 11 ..................................................................................................................................................... 37
Figure 12 ..................................................................................................................................................... 38
Figure 13 ..................................................................................................................................................... 40
Figure 14 ..................................................................................................................................................... 42
Figure 15 ..................................................................................................................................................... 43
Figure 17 ..................................................................................................................................................... 44
Figure 18 ..................................................................................................................................................... 45
Figure 19 ..................................................................................................................................................... 46
Figure 20 ..................................................................................................................................................... 47
Figure 21 ..................................................................................................................................................... 47
Figure 22 ..................................................................................................................................................... 49
Figure 23 ..................................................................................................................................................... 50

7


LIST OF TABLES

Table 1 ......................................................................................................................................................... 10
Table 2 ......................................................................................................................................................... 64
Table 3 ......................................................................................................................................................... 64
Table 4 ......................................................................................................................................................... 64
Table 5 ......................................................................................................................................................... 65
Table 6 ......................................................................................................................................................... 65
Table 7 ......................................................................................................................................................... 66
Table 8 ......................................................................................................................................................... 66








8

COMPANY PROFILE
BSES Corporate Profile
BSES, a Reliance Group Company, is the largest, fully integrated private sector Power Utility
company in the country, engaged in Generation, Transmission and Distribution of electricity
with an Annual Turnover in excess of Rs.8,000 crore. (US$ 1.2 billion) BSES have over five
million customers in Mumbai, Delhi and Orissa, the largest in India in the Private Sector. Our
Power Plants are located in Maharashtra, Kerala and Andhra Pradesh.
The Reliance Group founded by Mr. Dhirubhai H. Ambani (1932-2002) is India's largest
business house with total revenues of Rs. 80,000 crore (US$ 16.8 billion), cash profit of over Rs.
9,800 crore (US$ 2.1 billion), net profit of over Rs. 4,700 crore (US$ 990 million) and exports of
Rs. 11,900 crore (US$ 2.5 billion). The group's activities span exploration and production
(E&P) of oil and gas, refining and marketing, petrochemicals (polyester, polymers, and
intermediates), textiles, financial services and insurance, power, telecom and infocom
initiatives.









9

BSES, Delhi Network Overview
BSES YAMUNA POWER LTD which are a joint venture between Reliance Infra and Govt of
Delhi distribute power to Central, East, Delhi. As a 1
st
Milestone in road map towards Network
Automation, BSES proposes to implement a SCADA/DMS system in the Delhi Distribution
Network. Brief details of Delhi Distribution Network is given below.
Delhi draws power from 400kV Northern Grid at 400/220kV Mandola sub-station which is
interconnected with Bawana and Bamnauli sub-stations, at 220 kV through interconnection at
Patparganj (with Uttar Pradesh) and Narela (with Haryana) and at 220 KV Indra Prastha
Extension sub-station to Badarpur Thermal Power Station (BTPS). Delhi’s transmission system
at 220 kV consists of twenty-three 220 kV interconnected sub-stations.
The Transmission lines broadly comprise of 122 ckt.-kms of 400 kV and 529 ckt.-kms of 220 kV
lines. The 220 kV lines having ACSR Zebra conductor form a ring around Delhi region. The
transmission lines do not belong to BSES and are managed by other transmission company
(‘Transco’).

The power from these 220/66 & 220/33 kV substation of Transco is fed to BSES Delhi area by
various 99 input feeders at 66 & 33 kV voltage level.
There are 50 grid substation of 66/11 kV, 33/11 kV & 66/33 kV. The Primary distribution
network operates essentially at 11 kV (except for a few old 6.6 kV feeders) emanating from the
66 kV and/or 33 kV sub-stations. In many areas the 11 kV feeder network has the facility for
Ring Connection or interconnection with different zones. There are about 1200 numbers of such
11 kV feeders. These 11 kV feeders in turn are feeding to about 2500-distribution transformer of
11/0.4 kV.
A summary of the system parameters consisting of BSES Yamina Power Ltd (BYPL) areas is
given in the table below :


10








Table 1







Maximum demand 1195 MW
No of 66/11, 33/11 & 66/33 kV substation 50 nos
Total capacity at 66 & 33 Kv 2834 MVA
Power factor 0.85 -0.9
No. of 11kV Feeders 685 nos.
11kV OH Lines 250 kms.
11kV UG Cables 1756 kms.
Distribution Transformers 3261 nos.
Total Transformers capacity 2319 MVA
11


Delhi Network
Figure 1




12

Chapter -1
Introduction to SCADA:
The SCADA systems in use for Distribution systems like Water & Gas are existent for
several decades in USA and other developed countries; however the use of these systems
for electric distribution monitor & control is quite recent. In India also now we can see
the number of electric distribution projects – some are already in the operation and other
are in the implementation phase. The SCADA technology has been matured enough now
due to advances that has taken place in semiconductor technologies & telemetric. In the
document the discussion is limited to Electric SCADA & Distribution Automation
Systems.
The early SCADA systems were built on replicating the existing system remote controls,
lamps, and analog indications at the functional equivalent of pushbuttons, often placed on
a mimic board for easy operator interface. The SCADA masters simply replicated point-
for-point, control circuits connected to the remote, or slave, unit. At the same time as
SCADA systems were developing, a parallel technology on remote teleprinting , or
Teletype" was taking shape. The invention of the "modem" (Modulator / Demodulator)
allowed digital information to be sent over wire pairs which had been engineered to only
carry the electronic equivalent of human voice communication. The introduction of
digital electronics made it possible use of faster data streams to provide remote indication
and control of system parameters. The integration of Teletype technology and the digital
electronics gave birth to "Remote Terminal Units" (RTU‘s) which were built with solid-
state electronics which could provide the remote indication and control of both discrete
events and analog voltage and current quantities of the electric power system.
The development of Microprocessors gave the required impetus to SCADA industry
craving for increased functionality & faster speeds. The 1970s and early 1980s saw the
coming age of integrated microprocessor-based devices which came to be known as
"Intelligent Electronic Devices", or IED‘s. The IED‘s are being used increasingly to
convert data into engineering unit values in the field and to participate in field-based local
control algorithms. Many IED‘s are being built with programmable logic controller
(PLC) capability and, communication.
13




1.1Need for SCADA system:

Following are the main cause for SCADA need.

 Lack of Information Availability
 Poor Visibility
 Long Fault Restoration Times
 Inadequate Information for processing Customer requests
 Need for Real Time data for Network Analysis & Reconfiguration
 Need For Historical Information
 Load Forecasting and capacity planning.
 Asset tracking and management
 All Report generation
 Training and research.


Earlier methods used to acquire data:

 PLCC Network
 Wireless VHF sets
 P&T.FWP telephones
 Log sheets




14




Limitations of old method:

 Outage of telephone/PLCC network
 Non-clarity of speech
 Human factor
 No check on improper compliance of instruction
 Huge time require to collect data and pass instructions
 No control on operations





15

1.2BENEFITS OF SCADA?
 Visibility for the network operation.
 Real-time, accurate and consistent information of the system.
 Flexibility of operational controls.
 Faster fault identification, Isolation & system restoration.
 Extensive reporting & statistical data archiving.
 Central database and history of all system parameters.
 Improve availability of system, Optimized Load Shedding.

SCADA in distribution system & utilities is used for Distribution Automation, DMS, OMS i.e.
Distribution Management System and Outage Management respectively. These has been
implemented by a lot of distribution utilities across the world the achieve better monitoring and
control and to improve power quality, reliability & customer satisfaction.
The goal of Advanced Distribution Automation is real-time adjustment to changing loads,
generation, and failure conditions of the distribution system, usually without operator
intervention.
Presently the distribution utilities across the world are either implementing or have implemented
distribution automation solutions for fulfilling one or more of these business objectives:
 Better monitoring & control of their distribution assets
 To reduce their Aggregate Technical and Commercial (AT&C) losses
 As part of their Smart Grid compliance put by the regulation

SCADA systems are globally accepted as a means of real-time monitoring and control of electric
power systems, particularly for generation, transmission and distribution systems. RTUs
(Remote Terminal Units) are used to collect analog and status telemetry data from field devices,
as well as communicate control commands to the field devices. Installed at a centralized location,
such as the utility control center, are front-end data acquisition equipment, SCADA software,
16

operator GUI (graphical user interface), engineering applications that act on the data, historian
software, and other components.

Recent trends in SCADA include providing increased situational awareness through improved
GUIs and presentation of data and information; intelligent alarm processing; the utilization of
thin clients and web-based clients; improved integration with other engineering and business
systems; and enhanced security features.














17

CHAPTER-2
DISTRIBUTION SUBSTATION

A substation is a part of an electrical generation, transmission, and distribution system.
Substations transform voltage from high to low, or vice-versa, or perform any of several
other important functions. Electric power may flow through several substations between
generating plant and consumer, and its voltage may change in several steps.
A substation that has a step-up transformer increases the voltage while decreasing the
current while a step-down transformer decreases the voltage while increasing the current
for domestic and commercial distribution.

Substations may be on the surface in fenced enclosures, underground, or located in
special-purpose buildings. High-rise buildings may have several indoor substations.
Indoor substations are usually found in urban areas to reduce the noise from the
transformers, for reasons of appearance, or to protecstwitchgear from extreme climate or
pollution conditions.

Where a substation has a metallic fence, it must be properly grounded to protect people
from high voltages that may occur during a fault in the network. Earth faults at a
substation can cause a ground potential rise. Currents flowing in the Earth's surface
during a fault can cause metal objects to have a significantly different voltage than the
ground under a person's feet; this touch potential presents a hazard of electrocution.






18

Figure 2


19

2.1 TYPES OF SUBSTATIONS

Transmission substation: A transmission substation connects two or more transmission
lines. The simplest case is where all transmission lines have the same voltage. In such
cases, the substation contains high-voltage switches that allow lines to be connected or
isolated for fault clearance or maintenance. A transmission station may
have transformers to convert between two transmission voltages, voltage control devices
such as capacitors, reactors or static VAr compensator and equipment such as phase
shifting transformers to control power flow between two adjacent power systems.

Transmission substations can range from simple to complex. A small "switching station"
may be little more than a bus plus some circuit breakers. The largest transmission
substations can cover a large area (several acres/hectares) with multiple voltage levels,
many circuit breakers and a large amount of protection and control equipment (voltage
and current transformers, relays and SCADA systems).

Figure 3

TRANSMISSION SUBSTATION



20


Distribution substation
A distribution substation transfers power from the transmission system to the distribution system
of an area. It is uneconomical to directly connect electricity consumers to the high-voltage main
transmission network, unless they use large amounts of power, so the distribution station reduces
voltage to a value suitable for local distribution.
The input for a distribution substation is typically at least two transmission or sub transmission
lines. Input voltage may be, for example, 66 kV, or whatever is common in the area. The output
is a number of feeders. Distribution voltages are typically medium voltage, between 11 and
33 kV depending on the size of the area served and the practices of the local utility.
The feeders will then run overhead, along streets (or under streets, in a city) and eventually
power the distribution transformers at or near the customer premises.
Besides changing the voltage, the job of the distribution substation is to isolate faults in either the
transmission or distribution systems. In a large substation, circuit breakers are used to interrupt
any short or overload currents that may occur on the network. Distribution substations may also
be the points of voltage regulation, although on long distribution circuits (several km/miles),
voltage regulation equipment may also be installed along the line.
Complicated distribution substations can be found in the downtown areas of large cities, with
high-voltage switching, and switching and backup systems on the low-voltage side.








21

Figure 4

Distribution Substation

22


2.2 CLASSIFICATION OF SUBSTATION
1. According to service requirement

a) Transformer sub-station: Those sub-station which change the voltage level of electrical
supply is called Transformer sub-station.
b) Switching sub-station: This sub-station simply perform the switching operation of power
line.
c) Power factor correction S/S: This sub-station which improves the p.f. of the system are
called p.f. correction s/s. these are generally located at receiving end s/s.
d) Frequency changer S/S: Those sub-stations, which change the supply frequency, are known
as frequency changer s/s. Such s/s may be required for industrial utilization
e) Converting sub-station: That sub-station which change A.C power into D.C. power are
called converting s/s ignition is used to convert AC to dc power for traction, electroplating,
electrical welding etc.
f) Industrial sub-station: Those sub-stations, which supply power to individual industrial
concerns, are known as industrial sub-station.


2. According to constructional features

a) Outdoor Sub-Station: For voltage beyond 66KV, equipment is invariably installed
outdoor. It is because for such Voltage the clearances between conductor and the space
required for switches, C.B. and other equipment becomes so great that it is not
economical to install the equipment indoor.




23

Figure 5

OUTDOOR SUBSTATION


b) Indoor Sub-station: For voltage up to 11KV, the
equipment of the s/s is installed indoor because of economic consideration. However,
when the atmosphere is contaminated with impurities, these sub-stations can be erected
for voltage up to 66KV
Figure 6




Figure 7
24

c) Underground sub-station: In thickly populated areas, the space available for equipment
and building is limited and the cost of the land is high. Under such situations, the sub-
station is created underground. The design of underground s/s requires more careful
consideration.
 The size of the s/s should be as small as possible.
 There should be reasonable access for both equipment & personal.
 There should be provision for emergency lighting and protection against fire.
 There should be good ventilation

3. According to nature of duties

a) Step-up or Primary Substations- Where from power is transmitted to various load
centers in the system network and are generally associated with generating stations.

b) Step-up and Step-down or Secondary Substations- may be located at generating
points where from power is fed directly to the loads and balance power generated is
transmitted to the network for transmission to other load centers.

c) Step-down or Distribution Substations- receives power from secondary substations
at extra high voltage (above 66 kV) and step down its voltage for secondary
distribution.


4. According to operating voltage

a) High Voltage Substations (HV Substations) - involving voltages between 11
kV and 66 kV.

25

b) Extra high voltage substations (EHV Substations) - involving voltages
between 132 kV and 400 kV and

c) Ultra high voltage substations (UHV Substations) - operating on voltage above
400 kV

5. According to Importance

a) Grid Substations- These are the substations from where bulk power is transmitted
from one point to another point in the grid. These are important because any
disturbance in these substations may cause the failure of the grid.

b) Town Substations- These substations are EHV substations which step down the
voltages at 33/11 kV for further distribution in the towns and any failure in such
substations results in the failure of supply for whole of the town.





26


2.3 MAIN EQUIPMENTS USED IN A DISTRIBUTION SUBSTATION

A distribution substation is an assembly of various electrical equipments connected to step down
electric power at higher voltages i.e. 66kV/33kV to 11kV and to clear faults in the system. The
various electrical equipments used in the distribution substation are as follows:-
1. Power Transformers
2. Instrument Transformers i.e. CT, PT and CVT
3. Bus Bars
4. Isolators
5. Relays
6. Circuit Breakers
7. Lightening Arrestors
8. Battery chargers
9. Capacitor banks
10. Earthing equipments
11. Control and relay (C & R) panels
12. PLC’s or RTU (remote terminal units)
13. Multi function Meters


27

POWER TRANSFORMERS
A transformer is a device that transfers electrical energy from one circuit to another
through inductively coupled conductors—the transformer's coils. A varying current in the first
or primary winding creates a varying magnetic flux in the transformer's core, and thus a
varying magnetic field through the secondary winding.
It is the costliest equipment in a substation and important from the view of station layout.

One of the governing factors affecting the layout of a substation is that weather the transformer is
a 3 phase transformer or a bank of 3 single phase transformers. The space requirement with bank
of 3 single phase transformers is much more than a single 3 phase transformer. In case of a 3
single phase unit it is normal to provide one spare single phase transformer to be used in case of
a fault or if one of the single phase transformer is under maintenance. On account of large
dimensions it is very difficult to accommodate two transformers in adjacent bays. In order to
reduce the risk of spread of fire, large transformers are provided with stone pebble filled soaking
pits and oil collecting pits.

With transformers, however, the high cost of repair or replacement, and the possibility of a
violent failure or fire involving adjacent equipment, may make limiting the damage a major
objective. The protection aspects of relays should be considered carefully when protecting
transformers. Faults internal to the transformer quite often involve a few turns. While the
currents in the shorted turns are large in magnitude, the changes of the currents at the terminals
of the transformer are low compared to the rating of the transformer.









28

Figure 8


Instrument Transformer:

They are devices used to transform voltage and current in the primary system to values suitable
for measuring instruments, meters, protective relays etc.
They are basically the current transformers and voltage transformers.
a) Current transformers: It may be of bushing or wound type. The bushing types are
normally accommodated within the transformer bushing and the wound types are
separately mounted. When current in a circuit is too high to directly apply to measuring
instruments, a current transformer produces a reduced current accurately proportional to
the current in the circuit, which can be conveniently connected to measuring and
recording instruments.The CT is typically described by its current ratio from primary to
secondary.


29



b) Voltage transformers: It may be either capacitive type or electromagnetic type. The
electromagnetic type VTs are more expensive than capacitive type and are used where
higher accuracy is required. Capacitive type is usually preferred at high voltages due to
lower cost and secondly because it serves the purpose of coupling capacitor for the power
line carrier equipment. Voltage transformers are usually connected on the feeder side of
the circuit breaker. However they are also connected on the bus bar side for
synchronization. They step down extra high voltage signals and provide a low
voltage signal, for measurement or to operate a protective relay.

c) Capacitive Voltage Transformer (CVT’s): In combination with wave traps are used for
filtering high frequency communication signals from power frequency. This forms a
carrier communication network throughout the transmission network.

TAP CHANGER

A device used to increase or decrease a transformer's voltage to alter the level of current it can
draw (tap) from the circuit supplying electricity. Changing the tap of a transformer or regulator
serves the same function in an electrical circuit as turning the tap handle of a water faucet serves
to adjust water flow.


30


BUS-BARS
In electrical power distribution, a bus bar is a thick strip of copper or aluminum that
conducts electricity within a switchboard, distribution board, substation or other electrical
apparatus. Bus bars are used to carry very large currents, or to distribute current to multiple
devices within switchgear or equipment. Bus bars are typically either flat strips or hollow tubes
as these shapes allow heat to dissipate more efficiently due to their high surface area to cross
sectional area ratio.

The size of the bus bar is important in determining the maximum amount of current that can be
safely carried.

Bus bar may either be supported on insulators, or else insulation may completely surround it.
Bus bars are protected from accidental contact either by a metal enclosure or by elevation out of
normal reach. Bus bars may be connected to each other and to electrical apparatus by bolted or
clamp connections.

Various Bus bar Schemes
 Single Bus
 Single Bus with Bus Section
 Main & Transfer Bus.
 Double Bus.
 Main 1, Main 2 & Transfer Bus

CIRCUIT BREAKER
A circuit breaker is an automatically operated electricalswitch designed to protect an electrical
circuit from damage caused by overload or short circuit. Its basic function is to detect a fault
condition and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a
fuse, which operates once and then has to be replaced, a circuit breaker can be reset (either
31

manually or automatically) to resume normal operation. Circuit breakers are made in varying
sizes, from small devices that protect an individual household appliance up to large switchgear
designed to protect high voltage circuits feeding an entire city.

The type of the Circuit Breaker is usually identified according to the medium of arc extinction.
The classification of the Circuit Breakers based on the medium of arc extinction is as follows:
 Air break Circuit Breaker. (Miniature Circuit Breaker).
 Oil Circuit Breaker (tank type of bulk oil)
 Minimum oil Circuit Breaker.
 Air blast Circuit Breaker.
 Vacuum Circuit Breaker.
 Sulphur hexafluoride Circuit Breaker. (Single pressure or Double Pressure).


32

ISOLATOR
In electrical systems, an isolator switch is used to make sure that an electrical circuit is
completely de-energized for service or maintenance. Such switches are often found in electrical
distribution and industrial applications where machinery must have its source of driving power
removed for adjustment or repair. High-voltage isolation switches are used in electrical
substations to allow isolation of apparatus such as circuit breakers and transformers, and
transmission lines, for maintenance.

An isolator can open or close the circuit when either a negligible current has to be broken or
made or when no significant voltage change across the terminals of each pole of isolator occurs.
It can carry current under normal conditions and can carry short circuit current for a specified
time. They can transfer load from one bus to another and also isolate equipments for
maintenance. Isolators guarantee safety for the people working on the high voltage network,
providing visible and reliable air gap isolation of line sections and equipment. They are basically
motorized i.e. motor does the closing and opening of the isolator.

Isolators are distinguished as “off load” and “on load” isolator

Figure 9

ISOLATORS IN A SUBSTATION
33


EARTHING

The function of an earthing system is to provide an earthing system connection to which
transformer neutrals or earthing impedances may be connected in order to pass the
maximum fault current. The earthing system also ensures that no thermal or mechanical
damage occurs on the equipment within the substation, thereby resulting in safety to
operation and maintenance personnel. The earthing system also guarantees equipotential
bonding such that there are no dangerous potential gradients developed in the substation.
In designing the substation, three voltages have to be considered.
1. Touch Voltage: This is the difference in potential between the surface potential and
the potential at an earthed equipment whilst a man is standing and touching the earthed
structure.
2. Step Voltage: This is the potential difference developed when a man bridges a
distance of 1m with his feet while not touching any other earthed equipment.
3. Mesh Voltage: This is the maximum touch voltage that is developed in the mesh of
the earthing grid.

RELAYS
A relay is an electrically operated switch. Many relays use an electromagnet to operate a
switching mechanism mechanically, but other operating principles are also used. Relays
are used where it is necessary to control a circuit by a low-power signal (with complete
electrical isolation between control and controlled circuits), or where several circuits
must be controlled by one signal.
Relays with calibrated operating characteristics and sometimes multiple operating coils
are used to protect electrical circuits from overload or faults; in modern electric power
systems these functions are performed by digital instruments still called "protective
relays".

Types of relays:
34

 Electromagnetic attraction relay
 Electromagnetic induction relay
 Thermal relay
 Buchholz relay
 Numerical relay
 Over current relay

Control and relay panel
Control and relay panel of a grid substation has all controls, indications, meters and
protective relays mounted on the front. These panels are free-standing, floor mounting
type suitable chambers for indoor installation. Panels are rigid structural frames enclosed
completely with smooth finished rolled sheet steel. In every grid of BYPL the
instruments operate at 220V DC supply. The standard voltages of a grid are 220V DC
and 48V DC.
Thus, to supply 220V DC separate battery charger rooms are set up in the grid. DC is
supplied to avoid the failure of instruments in the absence of AC supply. Thus for
continuous operation of the grid DC is supplied to all instruments in a C & R panel.














35

Figure 10



Multifunction meters

The MFM is an IED that can calculate values once the inputs from the secondary of the
CTs and PTs have been given. Each MFM is dedicated to a particular panel, be it,
outgoing or incoming. The MFM calculates and displays values on a hand held
programming and display unit. These values depend on the programmed primary value
corresponding to the CT and PT ratio, pertaining to that feeder.

There is a communication port available for each MFM. It uses the RS 485 connection
scheme. The communication ports of five MFMs are looped. It is extended to the front
face of an SLI card through a cable. A maximum of 32 MFMS can be connected to one
single cable. The cable is then terminated at the A and B ports of the SLI cards, using an
RJ45 jack. In order to terminate the cable in port 1 and 2 of the SLI card, we have to
make use of a converter, which converts the RS 485 into a RS232 scheme.
36

The various values given by MFM (Multi Function Meter) which is the IED in this case
are:
 R phase Current (A)
 Y phase Current (A)
 B phase Current (A)
 R-Y phase Voltage (V)
 B-R phase Voltage (V)
 Y-B phase Voltage (V)
 Active Power (W)
 Reactive Power (VA)
 Power Factor
 Maximum Demand (W)



Capacitor Banks

A capacitor (originally known as condenser) is a passivetwo-terminalelectrical
component used to store energy in an electric field. The forms of practical capacitors vary
widely, but all contain at least two electrical conductors separated by a dielectric
(insulator); for example, one common construction consists of metal foils separated by a
thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in
many common electrical devices.
When there is a potential difference (voltage) across the conductors, a static electric field
develops across the dielectric, causing positive charge to collect on one plate and
negative charge on the other plate. Energy is stored in the electrostatic field. An ideal
capacitor is characterized by a single constant value, capacitance, measured in farads.
This is the ratio of the electric charge on each conductor to the potential difference
between them.

37

The capacitance is greatest when there is a narrow separation between large areas of
conductor, hence capacitor conductors are often called "plates," referring to an early
means of construction. In practice, the dielectric between the plates passes a small
amount of leakage current and also has an electric field strength limit, resulting in a
breakdown voltage, while the conductors and leads introduce an undesired inductance
and resistance.

Capacitors are widely used in electronic circuits for blocking direct current while
allowing alternating current to pass, in filter networks, for smoothing the output of power
supplies, in the resonant circuits that tune radios to particular frequencies, in electric
power transmission systems for stabilizing voltage and power flow, and for many other
purposes.
Figure 11

capacitor bank

38

Battery Charger

In a protection system it is necessary that control DC voltage shall remain always
constant for as much time as possible, so that system works without interruptions. The
charger is a rectifier which whichproduces slightly higher voltage compared to the
nominal cell voltage of a battery. The main source is derived from the normally available
AC source which is rectified by the charger.
Here the battery is combination of multiple cells connected ion series to get the nominal
DC tripping/control voltage required for the operation of relays and breakers and could
be from 24V to 220 V depending on loads and capacity requirements


Figure 12


Lightening arrestors

A lightning arrester is a device used on electrical power systems and telecommunications
systems to protect the insulation and conductors of the system from the damaging effects
39

of lightning. The typical lightning arrester has a high-voltage terminal and a ground
terminal. When a lightning surge (or switching surge, which is very similar) travels along
the power line to the arrester, the current from the surge is diverted through the arrestor,
in most cases to earth.

In telegraphy and telephony, a lightning arrestor is placed where wires enter a structure,
preventing damage to electronic instruments within and ensuring the safety of individuals
near them. Smaller versions of lightning arresters, also called surge protectors, are
devices that are connected between each electrical conductor in power and
communications systems and the Earth. These prevent the flow of the normal power or
signal currents to ground, but provide a path over which high-voltage lightning current
flows, bypassing the connected equipment. Their purpose is to limit the rise in voltage
when a communications or power line is struck by lightning or is near to a lightning
strike.


If protection fails or is absent, lightning that strikes the electrical system introduces
thousands of kilovolts that may damage the transmission lines, and can also cause severe
damage to transformers and other electrical or electronic devices. Lightning-produced
extreme voltage spikes in incoming power lines can damage electrical home appliances.

40


Figure 13


41

CHAPTER-3
Basics of RTU &
SCADA Adaptation
Remote Terminal Unit
The RTU or the Remote Terminal Unit is one of the components that comprise the
SCADA system. It gathers information that is present in the field or substation and sends it to the
Master Control Center (MCC). Similarly, it executes the command that come from the MCC. So,
we can say it is a two-way communication device that keeps updating the status of the field
continually and simultaneously executing the commands from the MCC.

RTU panels are divided into three parts one is RTU panel, 2
nd
is MFM panel and 3
rd
is
marshalling panel. Housing a stack of racks with electronic cards is called the “RTU Panel”.
Housing of only the MFMS or Multifunction Meters, called the “MFM panel”. The marshalling
panel is a junction which provides the connections of field signals to RTU .









42


Figure 14



The RTU panel consists of a Basic Rack&Extension Racks


43

Figure 15


Basic Rack: - The Basic rack or the Communication Rack houses the brain of the RTU. It
consists of nine slots. Into these slots are inserted a set of “Cards”. The Cards are the CPUs of
the RTU. They help in coordinating the flow of data from and into the RTU. These CPUs are
basically of two types.
1. SLI (Serial Line Interface) Cards
2. ETH (Ethernet) Cards


Figure 16

SLI (Serial Line
Interface) Card

44



Figure 17

Ethernet Card

The SLI Card acts as an interface between the RTU and the IEDs (Intelligent Electronic Devices)
like protection relays, multifunction meters, digital RTCC and battery charger.
SLI continually reads data from the IEDs. These IEDs could either be Numerical Relays
mounted on the CR Panel or an MFM placed on the MFM panel of the RTU It is generally
placed in a slot of the Basic Rack. The SLI card has got a provision for communicating with the
IEDs through four ports, A, B, 1 and 2. The port A and B are of the RS485 type where 1 and 2
are of the RS232. The SLI card has an serial MMI port for communicating with PC.
The ETH card controls the process events and communications with the Control Centers. It
continually reads the data from the Extension Racks, the SLI cards and sends it to the control
center. The ETH card has a port marked by “E” used by the RTU to communicate to the Master
control center. The either ports marked by “A” & “B” may use to connect the communication
from extension rack. Generally in our configuration port “B” using for this purpose. Similar as
45

SLI card It also has an serial MMI port for communication with PC or Lap-Top for
configuration and diagnosis purpose.
The ETH and the SLI cards communicate with each other through a dedicated communication
channel present on the back plane of the Basic Rack.

Figure 18



Extension Racks: - The Extension rack is a place, where Input/output Modules are placed.
Similar to the structure of the Basic Rack, the Extension rack has 19 slots into which the I/O
modules can be inserted. The extension rack communicates only with the ETH card of the Basic
Rack.
In cases where there are more than one extension rack, each communication port of the extension
rack is looped with the one succeeding it.
As mentioned before, the extension rack is connected to the ETH Card through port A or B,
called COM A and COM B.
46

The function of the Input Modules is to send the status of the equipment present in the grid
station to the MCC. Where as the function of the output modules is to control the status of the
equipment from the MCC. Thus, we see that the flow of data, in the case of input modules, is
from RTU to MCC and from MCC to RTU in the case of Output modules.

The different type of I/O modules used are the
DI cards – 23BE21
AI cards – 23AE21
DO cards. – 23BA20


Figure 19




47

Figure 20



Figure 21



The DI cards have 16 channels, which can be used for connecting the status of field devices as an
indication to MCC. If one takes a look at the front face of the DI card, who can see 16 LEDs,
Each LED indicates ON/OFF status of a input connected to particular channel of the DI card.
48

The AI card on the other hand gives the analog value of the signal. It has 8 channels on which
eight signals can be configured. The input to a channel in the AI card is a 4-20ma dc current,
which is proportional to the range of the analog value.

The DO card is used to execute commands that are sent from the MCC. As soon as the DO card
gets a command from the MCC, it sends a pulse of 48v dc to the exciting terminals of the
contactor(CMR). As soon as the contactor gets this pulse it closes its contacts and the command
gets executed.




















49

Figure 22

*
50



Communication Equipment:

Figure 23


The way the SCADA system network (topology) is set up can vary with each system but
there must be uninterrupted, bidirectional communication between the MTU and the RTU
for a SCADA or Data Acquisition system to function properly. This can be accomplished
in various ways, i.e. private wire lines, buried cable, telephone, radios, modems,
microwave dishes, satellites, or other atmospheric means, and many times, systems
employ more than one means of communicating to the remote site. This may include
dial-up or dedicated voice grade telephone lines, DSL (Digital Subscriber Line),
Integrated Service Digital Network (ISDN), cable, fiber optics, WiFi, or other broadband
services.
There are many options to consider when selecting the appropriate communication
equipment and can include either a public and/or private medium. Public medium is a
communication service that the customer pays for on a monthly or per time or volume
use. Private mediums are owned, licensed, operated and serviced by the user. If you
choose to use a private medium, consider the staffing requirements necessary to support
the technical and maintenance aspects of the system.
51



Private Media Types:

Private Wire
This type of media usually is limited to low bandwidth modems.


Wireless
(Spread Spectrum Radio)
This media type is license-free and available to the public in the 900 MHz and 5.8GHz
bands. The higher the frequency used in the system, the more "line of sight" it becomes.


Microwave Radio
Microwave radio transmits at high frequencies through parabolic dishes mounted on
towers or on top of buildings. This media uses point-to-point, line-of-sight technology
and communications may become interrupted at times due to misalignment and/or
atmospheric conditions.


VHF/UHF Radio
Good for up to 30 miles, VHF/UHF radio is an electromagnetic transmission with
frequencies of 175MHz-450MGz-900MHz received by special antennas. A license from
the FCC must be obtained and coverage is limited to special geographical boundaries.

Public Media Types:

(Telephone Company)
There are different services that your local telephone company can provide including:
Switched Lines, Private Leased Lines, Digital Data Service, Cellular and PCS/CDPD.
52


Switched Lines: Public Switch Telephone Network (PSTN) and Generally Switched
Telephone network (GSTN) are dial-up voice and data transmission networks furnished
by your local telephone company.

Private Leased Lines: Private Leased Lines (PLL) are permanently connected 24 hours a
day between two or more locations and used for analog (continuously varying signal)
data transmission.

Digital Data Service: Digital Data Service (DDS) is a private leased line with a special
bandwidth used to transfer data at a higher speed and lower error rate. This service is
applicable for computer-to-computer links.

Cellular: This service is equivalent to Switched Line services over landlines.
PCS/CDPD: This service is provided by cellular companies on a monthly fee or traffic
volume basis and is used when continuous communication is needed.


Other Media Types:

(WiFi-SMR)
Sometimes it makes sense to use the infrastructure of another company. WiFi equipment
utilizes broadband with high data rates and is used in a "time-share" basis to
communicate between sites of the system. This media type generally requires advanced
protocols like TCP/IP and network type connections.


(Satellite-Geosychronous/LEO)
Geosynchronous satellite's orbits are synchronous with the earth's orbit and remain in the
same position with respect to the earth. These satellites use high frequency transmissions
received by parabolic dish antennas. Low Earth Orbit (LEO) satellites hand off signals to
53

other satellites for continuous coverage and latency times are less than geosynchronous
satellites due to the lower orbit.






54

3.1 SCADA Applications:


Following are the main application commonly used.

 Network Connectivity Analysis (NCA)
 State Estimation (SE)
 Load Flow Application (LFA)
 Voltage VAR control (VVC)
 Load Shed Application (LSA)
 Fault Management and System Restoration (FMSR)
 Loss Minimization via Feeder Reconfiguration (LMFR)
 Load Balancing via Feeder Reconfiguration (LBFR)
 Operation Monitor (OM)
 Distribution Load forecasting (DLF)


Network Connectivity Analysis (NCA):

The network connectivity analysis function provides the connectivity between various
network elements. The prevailing network topology will be determined from the status of
all the switching devices such as circuit breaker, isolators etc. that affects the topology of
the network modeled.
NCA runs in real time as well as in study mode. Real-time mode of operation uses data
acquired by SCADA. Study mode of operation will use either a snapshot of the real-time
data or save cases. NCA can run in real time on event-driven basis.
The network topology of the distribution system will be based on

Tele-metered switching device statuses
Manually entered switching device statuses.

55

Modeled element statuses from DMS applications.

The NCA will be useful in determining the network topology for the following status of
the network.

Bus connectivity (Live/ dead status)

Feeder connectivity

Network connectivity representing S/S bus as node
Energized /de-energized state of network equipment
Representation of Loops (Possible alternate routes)
Representation of parallels
Abnormal/off-normal state of CB/Isolators

The NCA also assists the power system operator to know the operating state of the
distribution network indicating radial mode, loops and parallels in the network.
Distribution networks which are normally operated in radial mode; loops and/or parallel
may be intentionally or inadvertently formed.

State Estimation (SE)

The State Estimation (SE) is used for assessing (estimating) the distribution network
state. It shall assess loads of all network nodes, and, consequently, assessment of all other
state variables (voltage and current phasors of all buses, sections and transformers, active
and reactive power losses in all sections and transformers, etc.) in the Distribution
network.





56

Load Flow Application (LFA)

In Power system the quantities of electrical real & reactive power and Voltages are
complex quantities and the equations linking them are non-linear. At the load centres
(buses) the quantities of power both real & reactive will be known and at the power
generating points the real power and Voltage magnitudes will be available. The Load
flow analysis helps to evaluate the unknown quantities at all the buses for a given
network topology.
The Load Flow function shall provide real/active and reactive losses on:

Station power transformers , Feeders, sections, Distribution circuits including feeder
regulators and distribution transformers, as well as the total circuit loss, Phase voltage
magnitudes and angles at each node. Phase and neutral currents for each feeder ,
transformers, section.

Total three phases and per phase KW and KVAR losses in each feeder, section,
transformer, DT substation & for project area

Active & reactive power flows in all sections, transformers List of overloaded feeder,
lines, bus bars, transformers loads etc. including the actual current magnitudes, the
overload limits and the feeder name, substation name

List of limit violations of voltage magnitudes, overloading. Voltage drops and The LFA
utilizes information including real-time measurements, manually entered data, and
estimated data together with the network model supplied by the topology function, in
order to determine the best estimate of the current network state.

The Load Flow Application (LFA) determines the operating status of the distribution
system including buses and nodes. The LFA shall take the following into consideration
the following information:

Real time data
57

Manual entered data
Estimated data
Power source injections
Loops and parallels
Unbalanced & balanced loads
Manually replaced values
Temporary jumpers/ cut/ grounds
Electrical connectivity information from the real-time distribution network model
Transformer tap settings
Generator voltages, real and reactive generations.

Capacitor/reactor bank ON/OFF status value.

The LFA function can be executed at pre-defined events that affect the distribution
system. Some of the events the dispatcher may choose for triggers shall include:

Power system Topology Change i.e. Alteration in distribution system configuration.

Transformer Tap Position Change / Capacitive/reactor MVAR Change.

Feeder Over loadings.

Sudden change in feeder load beyond a set dead band


Volt –VAR control (VVC)
In electrical power system the reactive power can be generated at source generators or
can be injected at the substations through Volt-var systems. It is more appropriate to
inject at substations rather than producing then at generator points and transporting them
over long distances. Any power system always tries to optimize on the reactive power
flow over their networks.
58

The coordination of voltages and reactive power flows control requires coordination of
VOLT and the VAR function. This function shall provide high-quality voltage profiles,
minimal losses, controlling reactive power flows, minimal reactive power demands from
the supply network.
The following resources should be taken into account in any voltage and reactive power
flow control:

TAP Changer for voltage control

VAR control devices: switchable and fixed type capacitor banks.

Load Shed Application (LSA)
The power delivery to the consumers is also bogged down with the Demand-Supply
problems, with demand being always higher than supply. The reasons for less Supply are
several including the faults, tripping of lines. In these situations the power system
operator tries to Distribute available power


through Shedding of loads to consumers over small definite periods till he tides over the
situation of loss of power.
The load-shed application helps to automate and optimize the process of selecting the
best combination of switches to be opened and controlling in order to shed the desired
amount of load. Given a total amount of load to be shed, the load shed application shall
recommend different possible combinations of switches to be opened, in order to meet
the requirement. The dispatcher is presented with various combinations of switching
operations, which shall result in a total amount of load shed, which closely resembles the
specified total. The dispatcher can then choose any of the recommended actions and
execute them.
In case of failure of supervisory control for few breakers, the total desired load
shed/restore will not be met. Under such conditions, the application will inform the
dispatcher the balance amount of load to be shed /restore. The load-shed application runs
again to complete the desired load shed /restore process.
59

Fault Management & System Restoration (FMSR) Application

The availability of data related to the breakers/ switches and the level of The Fault
current flowing in the networks helps one to Manage & Restore the System in an event of
fault. This application helps to provide the assistance to the power system dispatcher for
detection, localization, isolation and restoration of distribution system after a fault in the
system has occurred with the help of operating through the supervisory control available
on SCADA. The devices which help in localization & isolation of the fault include Auto
Reclosures (AR), Sectionalisers, Fault Passage Indicators etc. The operation &
characteristics of these devices are separately addressed in the SCADA section.

Loss Minimization via Feeder Reconfiguration (LMFR)

The switching operation during fault and requirement to supply power through alternate
feeders in the distribution network modifies the feeder configuration topology. The
information of network topology and availability of adjacent feeder networks can be
useful in right selection of feeders with overall aim of reducing the line losses and
maximum power delivery to consumers.

This function identifies the opportunities to minimize technical losses in the distribution
system by reconfiguration of feeders in the network for a given load scenario. The
technical losses are the losses created by characteristic of equipment & cable such as
efficiency, impedance etc.
The function helps in calculation of the current losses based on the loading of all
elements of the network. The Telemeter values, which are not updated due to telemetry
failure, can also be considered by LMFR application based on arriving at the
recommendations of LF Application. The LMFR application can be utilized to have the
various scenarios for a given planned & unplanned outages, equipment operating limits,
tags placed in the SCADA system while recommending the switching operations.

Load Balancing via Feeder Reconfiguration (LBFR)

60

The discussions had on previous topic can be used for the Load Balancing via Feeder
Reconfiguration for the optimal balance of the segments of the network that are over &
under loaded. This helps in better utilization of the capacities of distribution facilities
such as transformer and feeder ratings.
The Feeder Reconfiguration Function can be used also to have a scenario on an overload
condition, unequal loadings of the parallel feeders and transformers, periodically or on
demand in the network by the dispatcher. The system will help generate the
switchingsequence to reconfigure the distribution network for transferring load from
some sections to other sections. The LBFR application can even consider the planned &
unplanned outages, equipment operating limits, tags placed in the SCADA system while
recommending the switching operations.
The function helps in distributing the total load of the system among the available
transformers and the feeders in proportion to their operating capacities, considering the
discreteness of the loads, available switching options between the feeder and permissible
intermediate overloads during switching. The dispatcher can have the options to simulate
switching operations and visualize the effect on the distribution network by comparisons
based on line loadings, voltage profiles, load restored, system losses, number of affected
customers.

Load Forecast (LF)

The Distribution Automation system keeps logging data periodically of the network. This
historical database and weather conditions data collected over a period can be used for
prediction and to have forecasting of the requirement of consumer loads. Generally there
are two types of forecasting that are resorted too.
Short-Term Load Forecasting (STLF) will be used for assessment of the sequence of
average electrical loads in equal time intervals, from 1 to 7 days ahead. The Long term
forecasting is used for forecasting load growths over longer durations. The fore casting
techniques are based on different forecasting methods such as Autoregressive, Least
Squares Method, Time Series Method, Neural, Kalman filter and Weighted Combination.

61

CHAPTER 4:
FINANCIAL MODELING (SOLAR PV PLANT)



5.1 Introduction

Renewable power generation capacity in India has been set up largely through private sector
investments. New investment is the most potent indicator of growth of the sector. As per an
estimate, in 2009 the total financial investment in clean energy in India was at INR 135 billion.
India ranked the ninth most attractive country for renewable energy investment in the world,
behind the United States, China, and Germany.
35
But highly aggressive bidding by developers in
increasing fierce competitive environment and uncertainty regarding the various costs incurred;
increases the risk associated with making an investment in setting up solar power plant.

A financial model helps the developer to explore in detail the financial benefits and costs
associated with the investment. This facilitates the identification of key variables affecting the
project value and enables financing decisions.The following section describe the key items and
assumptions that are included in the financial modeling of a typical Indian solar PV project, and
discusses the conclusions based on the calculation of various financial parameters.

5.2 Assumptions

Capital Costs

The normative capital cost for setting up Solar Photovoltaic Power Project shall be 1000
Lakh/MW for FY 2012-13 as per CERC (Terms and Conditions for Tariff determination from
Renewable Energy Sources) Regulations, 2012. But the recent drop in module cost accompanied
by increase in level of competition has dragged down the overall project cost quite substantially.


62

Operations and Maintenance (O&M) Cost

One of the major benefits of Solar PV power plants is less O&M costs as compared to other
renewable energy technologies. In the financial model O&M has been taken as per prevailing in
the industry.


Annual Energy Yield

There are a number of factors (e.g. Air pollution, shading, soiling, ambient temperature, module
quality, DC cable resistance, invertor performance, AC losses, downtime etc.) which affect the
annual energy yield of a solar PV project. The confidence level of the yield forecast is important,
as the annual energy yield directly affects the annual revenue. The energy yield prediction
provides the basis for calculating project revenue. The aim of an energy yield analysis is to
predict the average annual energy output for the lifetime of the proposed power plant. Typically,
a 25 to 30 year lifetime is assumed. Energy yield prediction reports should consider and (ideally)
quantify each of these losses. In the financial model energy yield prediction for 25 years is made
taking into account annual deration.




Energy Price

Besides the power generated, the solar PV project revenue is dependent upon the power price.
This may be fixed or variable according to the time of day or year, and must be clearly stipulated
in the power purchase agreement. Economic return has historically been the key limiting factor
for development of large scale grid-connected solar PV projects. PV has a high initial capital
cost. High energy prices are required for projects to be economic. Currently, grid-connected solar
projects are highly dependent on policy support initiatives such as grants, feed-in tariffs,
concessional project funding and mandatory purchase obligations.

63

The financial model has been made with flexibility to know various financial indicators with 3
power selling options:

1. Selling to State Discom at APPC.

2. Selling through open access to HT consumer.

3. Selling to power exchange at a market determined price.


Certified Emission Reductions (CERs)


As India is a non-Annex 1 party under the UN Clean Development Mechanism (CDM),
qualifying Indian solar projects could generate Certified Emission Reductions (CERs). These
CERs can then be sold to Annex 1 parties and help them comply with their emission reduction
targets. This effectively causes transference of wealth from Annex 1 parties such as the UK and
Germany to Indian developers.
Each CER is equivalent to the prevention of one tonne of carbon dioxide emissions. The income
from CERs can be substantial. However, this revenue source cannot be predicted as it is
uncertain whether the project will be accredited. Moreover, CER values fluctuate considerably.

The National CDM Authority under the Ministry of Environment and Forests (MoEF) is the
designated authority in India for approving CDM projects. The model has the flexibility of
taking into account approximate revenue from sale of CERs

Financing Assumptions


The project financing structure generally comprises of debt and equity.The general financial
assumptions for a project in India are as follows:

64

• Financing structure – equity 30% and debt 70% as assumed in CERC tariff order.

• Debt repayment period – 10-12 years (approx.).

The following table shows assumptions taken for calculation in financial model.

Table 2
Plant Details

Installed Capacity MW 5
CUF % 17.12%
Annual Deration % 0.75%
AUX % 0.25%
Useful Life Years 25

Table 3

Capital Structure

Debt % 70%
Equity % 30%
Total Debt Amount Mn 325.7062147
Total Equity Amount MN 139.5883777

Project Cost INR Mn/MW INR Mn
EPC 80 400
Land 5 25
Development Cost 3.5 17.5
IDC 22.79459241
Total project Cost 465.2945924
Table 4

65

Table 5
CDM Benefits No Yes
CERs per MU 950
Rate per CER Euro 4
1 Euro INR 66.16
Rate per CER INR 264.64
Estimated Period of Availability Years 10
80 IA Benefit (1="Yes", 2="No") 1
UNFCCC Adaptation Fee 2.00%
Revenue Retained (in 1st year) 100%
Incremental Share of Beneficiary (p.a.) 10%
Min. Retained Revenue 50%

Table 6

Taxes

Basic Tax 30%
Add: Surcharge 5.00%
Add: Cess 3%
Net Corporate Tax 32.45%
0.00%
Min. Alternate Tax 18.50%
Add: Surcharge 5.00%
Add: Cess 3.00%
Net MAT 20.01%
Start Year Year
Tax Exemption u/s 80 IA 8 10 100.00%






66


Table 7

Debt Schedule

Loan Amount Mn 325.71
Moratorium Period No. Of Quarters 0
Repayment Period Years 7
Repayment Period (Incl Moratorium) Years 7
Repayment Style Quaterly
Interest on Term Loan 13%
Interest on WC 12%


Table 8

Const. Time Table
Construction Start Date 1-Apr-12
Time in
Construction Months 12
COD 1-Apr-13

Misc.
Land
appreciating @ p.a. 5%
Discount Rate 20.00%





67


Working
Capital
O&M Charges Months 1
Receivables for Debtors Months 1
Maintenance
Spare (% O&M Exp.) 15%
WC Loan 100%

Depreciation
Companies Act
Depreciation Rate for first
10 years per annum 5%
Aggregate Dep. in first 10
years % 50%
Total allowed Depreciable
Value % 100%
Depreciation Rate from 11 year
onwards
%
p.a. 3.33%
Income Tax
Act
Depreciation
Rate
on
WDV 80%







68


REC
Control Period Ending
on -->
1-Apr-
12 1-Apr-17 1-Apr-22
1-Apr-
27 1-Apr-32
1-Apr-37 1-Apr-
42
% Reduction in Price 20% 100% 25% 25% 25%
Forbearance
Price
(Rs/KWh
) 17 13.4 10.72 0 0 0 0
Floor Price
(Rs/KWh
) 12 9.3 7.44 0 0 0 0


Note: The model is developed with flexibility to change the input field in cells with back ground

color







5.3 Project Economics and Financial Indicators

Project financial model calculates a range of project value indicators in order to allow
developers, lenders, investors and relevant government bodies to assess the project economics
from several perspectives.

From an investor’s point of view, a project is generally considered to be a reasonable investment
only if the internal rate of return (IRR) is higher than the weighted average cost of capital
(WACC). Investors will have access to capital at a range of costs; the return arising from
investment of that capital must be sufficient to meet the costs of that capital. Moreover, the
investment should generate a premium associated with the perceived risk levels of the project.
69


Solar projects are usually financed with equity and debt components. As a result, the IRR for the
equity component can be calculated separately from the IRR for the project as a whole. The
developer’s decision to implement the project or not, will be based on the equity IRR.

As returns generated in the future are worth less than returns generated today, a discount can be
applied to future cash flows to present them at their present value. The sum of discounted future
cash flows is termed the net present value (NPV). Investors will seek a positive NPV, assessed
using a discount rate that reflects the WACC and perceived risk levels of the project.

Lenders will be primarily concerned with the ability of the project to meet debt service
requirements. This can be measured by means of the debt service coverage ratio (DSCR), which
is the cash flow available to service debt divided by the debt service requirements. The Average
DSCR represents the average debt serviceability of the project over the debt term. A higher
DSCR results in a higher capacity of the project to service the debt. Minimum DSCR represents
the minimum repayment ability of the project over the debt term. A Minimum DSCR value of
less than one indicates the project is unable to service the debt in at least one year.

Based on assumptions taken and calculations
36
done in financial model following are values of
various financial indicators.



Project Economics

Project IRR 18.03%
Equity IRR 21.56%
Min DSCR 1.027023
Avg. DSCR 1.2971679


70


5.4 Sensitivity Analysis

Sensitivity analysis involves changing the inputs in the financial model (such as power tariff,
capital cost, interest rate etc.) to analyze how the value of the project changes (measured using
Net Present Value, Internal Rate of Return, or the Debt Service Cover Ratio).
Sensitivity analysis gives lenders and investors a greater understanding of the effects of changes
in inputs on the project’s profitability and bankability. It helps them understand the key risks
associated with the project. Lenders will conduct sensitivity analysis around the key variables in
order to determine whether the project will be able to service the debt in a bad year, for example
if energy yield is lower than expected, or operational expenditure is higher than expected.


Following sensitivity analysis was done

1. Effect of ‘Time Taken in Construction’ on financial parameters viz. Project IRR, Equity
IRR,Minimum DSCR and Average DSCR. The effect can be seen in table below.
Time in
Project Equity Min. Avg.

IRR IRR DSCR DSCR

Const.



(Months)

4 18.20% 21.87% 1.0367 1.3039
5 18.13% 21.74% 1.0327 1.3011
6 18.03% 21.56% 1.0270 1.2972
7 17.94% 21.39% 1.0215 1.2933
8 17.84% 21.22% 1.0161 1.2896
9 17.75% 21.05% 1.0108 1.2859
10 17.66% 20.89% 1.0055 1.2823
11 17.57% 20.73% 1.0004 1.2787
12 17.49% 20.57% 0.9954 1.2752




71




16.00% 14.40%


15.50%
14.20%


14.00%
P
r
o
j
e
c
t

I
R
R


E
q
u
i
t
y

I
R
R

15.00%



13.80%



14.50% 13.60%

14.00%
13.40%


13.20%

13.50%




13.00%



13.00% 12.80%


4 5 6 7 8 9 10 11 12



Months of Construction

Equity IRR

Project
IRR










2. Effect of REC trade price on Financial Parameters

CERC has given Forbearance Price and Floor Price for REC. RECs are traded in power
exchanges between these two price ranges. But the current Floor and Forbearance price
is applicable till March 2017. After that REC price is expected to go down.

Some developers are of the view that once grid parity is achieved the government may with
draw the mechanism. Though, these are just speculations.
72


The following table shows the how financial indicators viz. Project IRR, Equity IRR and
Average DSCR will vary with change in price at which REC would be traded post 2017. It
is evident that if RECs are traded below a certain level then the project’s viability will be
jeopardized.




Period From COD 1-Apr-17 1-Apr-22 1-Apr-27 1-Apr-32 1-Apr-37 Project
IRR
Equity
IRR Avg DSCR

Till 1-Apr-17 1-Apr-22 1-Apr-27 1-Apr-32 1-Apr-37 -


9.3 7.44 - - - - 18.03% 21.56% 1.29
REC Trade 9.3 5.58 - - - - 17.42% 20.47% 1.24
Price 9.3 4.65 - - - - 17.05% 19.80% 1.19
(Rs/KWh) 9.3 4.65 2.325 - - - 17.45% 20.43% 1.19
9.3 - - - - - 15.16% 16.59% 0.98
















73

5.5 Limitations of Financial Model


The financial model (attached) is developed with the solely objective of learning the
intricacies of financial modeling. Values in various input fields (like Tax Rate, EPC Cost
etc.) may not be correct.

The financial model developed is not perfectly flexible. It has some constraints while
entering the input fields like

Moratorium Period can be either 0 or 1 or 2 years

Date of commissioning is hard fixed to be April 1, 2013
Debt service to bank is done quarterly. Etc.
74

CHAPTER-5
CONCLUSION

All the above implementations are one of their kinds, both plays a very important role in
increasing the efficiency of the distribution company. The sub clustering of distribution
transformers provide a greater accuracy in pin pointing the affected area, the area which have to
be considered more for loss correction method.
This can result into few goods and beneficial aspect for the auditing division, such as:
1. It will increase the efficiency of the auditing division.
2. It will generate a sort of accuracy in data collection.
3. It can also pin point the area of maximum losses and take the corrective measures to reduce
these losses.

The DT automation process provides the complete safeguard from irregularities of DT health
reports and correction and monitoring of all the distribution transformers. It shall provide
unparalleled capabilities in monitoring, controlling, optimizing the efficiencies of the energy
meter. Implementation of an MDMS (Meter Data Management System) and integration of real
time Transformer data, distribution automation systems provide the information and intelligent
control necessary to facilitate the field operation remotely. It is an enabler that would foster
energy efficiency, interaction, proactive decisions and innovative practices to optimize power
usage. DT reports are very crucial and informative tool in reduction of AT&C losses.
Though total Payback Period is very high around 30 years, but the system will lead to substantial
improvement in Quality of supply, reduction of O&M expenses and increased customer
satisfaction. Energy Audit on real time basis will help in substantial reduction of AT & C Losses.

75

CHAPTER-7
REFERENCES

1. Detail Project Reports of BSES Yamuna
2. www.indianbusiness.nic.in
3. www.energywatch.org.in
4. www.projectmonitor.com
5. www.investopedia.com
6. www.cea.nic.in
7. www.sari-energy.org
8. www.google.com