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

ASHISH KUMAR

MBA Power Management

Roll No: 22 ; 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 3rd

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 SCADA15

1.2 BENEFITS OF SCADA..17

CHAPTER 2 DISTRIBUTION SUBSTATIONS19

2.1 TYPES OF SUBSTATIONS21

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 APPLICATIONS56

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 1st 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). Delhis 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

Chapter -1

Introduction to SCADA:

12

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" (RTUs) 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 IEDs. The IEDs are being used increasingly to

convert data into engineering unit values in the field and to participate in field-based local

control algorithms. Many IEDs 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. PLCs 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 conductorsthe 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 (CVTs): 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, 2nd

is MFM panel and 3rd

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 investors 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

developers 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 calculations36

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 projects 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%

Pro

ject

IR

R

Eq

uit

y I

RR

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 projects 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