REPORT ON 220 kV GSS RRVPN KOTPUTLI

1. A
seminar report submitted in partial fulfillment of the award
of
Bachelors of Technology in Electrical Engineering
on
“220 KV GSS RRVPNL KOTPUTLI (JAIPUR)”
Submitted to: Submitted by:
Dr.Seema Agarwal Name: Sneha Kanwar
Assistant Professor Roll no: (20/253)
UD RTU, Kota Year: 3rd
UNIVERSITY DEPARTMENT OF ELECTRICAL ENGINEERING
RAJASTHAN TECHNICAL UNIVERSITY KOTA

2. CERTIFICATE

3. ACKNOWLEDGEMENT
This is my first practical training which has taken at 220 KV GSS, KOTPUTLI.
I would like to express my sincere thanks to Mr. Ram Singh Yadav, who have given his excellent
guidance and shared his experience with me using entire course of training report.
I would like to thank other staff member which are guided me. Finally I would like to say this
summer training has been a valuable part in my life.
At last but not least I am thankful to all the staff member of “DEPARTMENT OF
ELECTRICAL ENGINEERING”.

4. PREFACE
This is training of 45 days; my training place was 220 KV GSS, KOTPUTLI (JAIPUR). GSS is
the mean of connection between generating station and consumer by providing safety and
reliability of system in case of default.
This sub station steps down the incoming voltage power transmission to the required value and
then is supplied to the consumer feeder or GSS done by connecting auto transformer operation
and requirement of various equipment have been include in detail , further in case of report is the
bus bar.
Arrangement of different feeder level and switch yards included information of bus bar
arrangement of different level isolator and growing substation also power transformer circuit
breaker oil, compression protection control room and place are levelled.

5. LIST OF ABBREVIATION
X-mer Transformer
CT Current Transformer
PT Potential Transformer
CB Circuit Breaker
VT Voltage Transformer
PLCC Power line carrier communication
kV Kilovolts

6. INDEX
S.N. CONTENTS P.N.
1. INTRODUCTION 1-3
2. SINGLE LINE DIAGRAM 4
3. SUBSTATION 5-7
4. PANEL SECTION 8
5. SWITCH YARD 9
6. TRANSFORMER 10-14
7. CAPACITOR BANK 15
8. PLCC 16
9. ISOLATOR 17
10. CIRCUIT BREAKER 18
11. LIGHTENING ARRESTER 19-20
12. RELAY & PROTECTION PANEL 21-23
13. INSULATOR 24
14. WAVE TRAPPER 25
15. BUS BAR 26
16. BATTERY ROOM 27-28
17. MEGGER INSULATING TESTER 29
18. MULTIMETER 30
19. CLOSING COIL 31
20. CONCLUSION 32
21. REFERENCES 33

7. Chapter-1
INTRODUCTION
When India becomes independent its overall installed capacity was hardly 1900 mw. During first
year plan (1951-1956) this capacity was only 2300 mw. The contribution of Rajasthan state was
negligible during 1&2 year plans the emphases was on industrialization for that end it was
considered to make the system of the country reliable. Therefore Rajasthan state electricity board
came into existence in July 1957.
In India electrical power is generated at a voltage of 11KV to 33 KV. This is taken stepped up to
the transmission level in the range of 66 KV to 400 KV.
Member of transmission and switching have to be created. These are known as "SUB
STATION".
Along these transmission lines secondary substation are created where voltage is further stepped
down to sub transmission and primary distribution voltage.
A substation is an assembly of apparatus, which transform the characteristics of electrical energy
from one form to another say from one voltage level to another level. Hence a substation is an
intermediate link between the generating station and consumer.
For economic transmission the voltage should be high so it is necessary to step up the generated
voltage for transmission and step down transmitted voltage for distribution. For this purpose
substations are installed. The normal voltages for transmission are 400kv, 220kv, 132kv and for
distribution 33kv, 11kv etc.
Electricity boards are setup in all states of India which are responsible for
1. Generation
2. Transmission
3. Distribution
1

8. They also construct, install and maintain all the station made for these purpose. In Rajasthan,
R.R.V.P.N.L. is responsible for transmission and distribution of electrical power all over
Rajasthan. It has its own generating station and it's also gets power from various other stations
also. It gets power from following stations:
1. Badarpur Thermal Power Station Delhi
2. Bhakara Nangl Project (at satlaj in Punjab)
3. Gandhi Sagar Dam Kota
4. Jawahar Dam Kota
5. Rana Pratap Sagar Dam Kota
6. Rajasthan Atomic Power Plant (RAPP) Kota
7. Kota Super Thermal Power Station (KSTPS) Kota
8. Anta Gas Power Plant Anta
9. Rajasthan share in Bhakara Beas Management Board (BBMB)
Power obtain from these stations is transmitted all over Rajasthan with the help of grid stations.
Depending on the purpose, substations may be classified as:
1. Step up substation
2. Primary grid substation
3. Secondary substation 4. Distribution substation.
5. Bulky supply and industrial substation
6. Mining substation
7. Mobile substation
8. Cinematograph substation
Depending on constructional feature substation are classified as:
• Outdoor type
• Indoor type
• Basement or Underground type
• Pole mounting open or kilos type
Any substation has many types of civil and electrical works.
2

9. Main components are:
• Bus bar
• Power transformers
• Isolators
• Circuit breaker
• Lightening arrester
• Insulators
• Instrument transformers
The control room is equipped with protective relays, ammeters, voltmeters, energy meters
and frequency and power factor meters.
D.C. supply is heart of GSS batteries are used for this purpose. They have separate
charging circuit also. For communication purpose P.L.C.C. is used which has its various
components.
220 KV GSS, Kotputli is the part of the transmission system.
INCOMING FEEDER:
220 KV Heerapura Line
• 220 KV Manoharpura Line
• 220KV Neemrana Line
• 220KV Bansur Line
• 220KV Pgcil-khelna line
OUTGOING FEEDER:
• 132 K.V.
1. Keshwana Line
2. Bansur Line
3. Paota Line
4. Grasim Line
33 K.V
1. Badabas
2. Pathredi
3. Putli
3

10. Chapter-2
SINGLE LINE DIAGRAM OF 220 KV G.S.S

11. Chapter-3
SUBSTATION
A substation is part of an electrical generation, transmission, and distribution system.
Substations transform voltage from high to low, or the reverse, or perform any of several
other important functions.
Elements of a substation
A: Primary power lines' side
B: Secondary power lines' side
1. Primary power lines
2. Ground wire
3. Overhead lines
4. Transformer for measurement of electric voltage
5. Disconnect switch
6. Circuit breaker
7. Current transformer
8. Lightning arrester
TYPES OF SUBSTATION:-
Transmission substation: - A transmission substation connects two or more transmission
lines. The simplest case is where all transmission lines have the same voltage.
Distribution substation: - A distribution substation transfers power from the transmission
system to the distribution system of an area.
Collector substation: - In distributed generation projects such as a wind farm or
photovoltaic power station, a collector substation may be required.
Converter substations:- Converter substations may be associated with HVDC converter
plants, traction current, or interconnected non-synchronous networks.
Switching station:- A switching station is a substation without transformers and operating
only at a single voltage level. Switching stations are sometimes used as collector and
distribution stations.
5

12. Railways:- Electrified railways also use substations, often distribution substations. In
some cases a conversion of the current type takes place, commonly with rectifiers for
direct current (DC) trains, or rotary converters for trains using alternating current (AC) at
frequencies other than that of the public grid.
Mobile substation:- A mobile substation is a substation on wheels, containing a
transformer, breakers and bus work mounted on a self contained semi-trailer, meant to be
pulled by a truck.
Fig1- Substation
6

13. 7
Substation
Panel section Switch yard
Control panel
section
Relay and
protection panel
section
1. 220KV
2.132KV
3. 33KV

14. PANEL SECTION
 It is a room which contains all types of panels.
 It has two sections:-
1. Control Panel Section It contains panels related to controlling of
instruments. E.g.:- Feeder panel, Transformerpanel, etc.
2. Relay and Protection Panel Section
It contains panels related to relay systems and protection systems.
E.g.:- Relay panel, line protection panel, etc.
Fig 2- Panel section
8

15. SWITCH YARD
It is the field where components used in controlling supply and measuring supply
(incoming and outgoing) are placed.
Some of these components are:-
1.Circuit breaker
2. Isolators
3. Current transformer
4. Potential transformer
5 . Lightning arrester
6. Transformer, etc.
Fig 3 - Switch Yard

16. 9
TRANSFORMER
A transformer a passive is defined as electrical device that transfers electrical energy from
one circuit to another through the process of electromagnetic induction. It is most
commonly used to increase (‘step up’) or decrease (‘step down’) voltage levels between
circuits.
Parts of Transformer
 Core
 Winding(H.V winding, L.V winding, tertiary winding)
 X-MER oils
 Pressure relief valve
 Breather
 Conservator
 Radiator
 Tap changer
 Tank
Working Principle of Transformer
The working principle of a transformer is very simple. Mutual induction between two or
more windings (also known as coils) allows for electrical energy to be transferred between
circuits.

17. 10
TYPES OF TRANSFORMER
1. POWER TRANSFORMER
An autotransformer (or auto transformer) is a type of electrical transformer with only
one winding. The “auto” prefix refers to the single coil acting alone (Greek for “self”)
– not to any automatic mechanism. An auto transformer is similar to a two winding
transformer but varies in the way the primary and secondary winding of the
transformer are interrelated.
Fig 4 - Power Transformer

18. 11
2. INSTRUMENT TRANSFORMER-
Instrument transformers means current transformer and voltage transformer are used
in electrical power system for stepping down currents and voltages of the system for
metering and protection purpose. Actually relays and meters used for protection and
metering, are not designed for high currents and voltages. High currents or voltages of
electrical power system can not be directly fed to relays and meters. Current
transformer steps down rated system current to 1 Amp or 5 Amp similarly voltage
transformer steps down system voltages to 110 V. The relays and meters are generally
designed for 1 Amp, 5 Amp and 110 V.
Fig 5- Instrument Transformer
12

20. CURRENT TRANFORMER
Current transformer is a type of instrument transformer that is used in power system for
measurement, detection, protection of the system.
When current in a circuit is too high to apply directly measuring instruments, a CT produces a
reduced current accurately proportional to the current in the circuit, which can be
conveniently connected to measuring and recording instruments.
Fig 6 - Current Transformer
13
Instrument
transformer
Current
transformer
Potential
transformer

21. POTENTIAL TRANSFORMER
 Potential transformers are instrument transformers. They have a large number of primary
turns and a few numbers of secondary turns.
 It step down the voltage to something that meters can handle.
Fig 7 - Potential Transformer
14

22. CAPACITOR BANK
 A capacitor bank is used for reactive power compensation and power factor correction in
the power substations.
 The capacitor bank is connected in two ways – star and delta.
 The capacitor bank used in substation for the following reasons.
1. It will improve and correct the power factor.
2. It will control the level of supply voltage.
3. It will improve the power handling capacity of substation.
Fig 8 - Capacitor Bank
15

23. POWER-LINE CARRIER COMMUNICATION
Power-line carrier communication (PLCC) is mainly used for telecommunication,
teleprotection and tele-monitoring between electrical substations through power lines at
high voltages, such as 110 kV, 220 kV, 400 kV.......................The carrier frequency range is
used for audio signals, protection and a pilot frequency.
Fig 9 - PLCC
16

24. ISOLATOR
The isolator is a mechanical switch which isolates a part of the circuit from the system as when
required. Electrical isolators separate a part of the system from rest for safe maintenance works. So
the definition of isolator can be rewritten as an isolator is a manually operated mechanical switch
which separates a part of the electrical power. Isolators are used to open a circuit under no load. Its
main purpose is to isolate one portion of the circuit from the other and is not intended to be opened
while current is flowing in the line. Isolators are generally used on both ends of the breaker so that
repair or replacement of circuit breaker canbe done without any danger.
Fig 10 - Isolator
17

25. CIRCUIT BREAKER
A circuit breaker is an automatically operated electrical switch designed to protect an
electrical circuit from damage caused by excess current from an overload or short circuit. Its
basic function is to interrupt current flow after a fault is detected. Unlike a fuse, which
operates once and then must be replaced, a circuit breaker can be reset (either manually
or automatically) to resume normal operation.
Fig 11 - Circuit Breaker
18

26. LIGHTENING ARRESTERS
The device which is used for the protection of the equipment at the substations against
travelling waves, such type of device is called lightning arrester or surge diverter. In other
words, lightning arrester diverts the abnormal high voltage to the ground without affecting
the continuity of supply. It is connected between the line and earth, i.e., in parallel with the
equipment to be protected at the substation.
Fig 12 - Lightening arrester
The following are the damages that are caused by the travelling wave on the
substationequipment.
1. The high peak or crest voltage of the surge may cause flash-over in the internal winding
thereby spoil the winding insulation.
2. The steep wave fronts of the surges may cause external flashover between the terminals
of the transformer.
3. The highest peak voltage of the surge may cause external flashover, between the
terminals of the electrical equipment which may result in damage to the insulator.
19

27. LOCATION OF LIGHTNING ARRESTER
The lightning arrester is located close to the equipment that is to be protected. They are
usually connected between phase and ground in an AC system and pole and ground in case of
the DC system. In an AC system, separate arrester is provided for each phase. In an extrahigh
voltage AC system, the surge diverter is used to protect the generators, transformers, bus
bars, lines, circuit breakers, etc. In HVDC system the arrester is used to protect the buses,
valves converter units’ reactors, filter, etc.
20

28. RELAY AND PROTECTION PANEL
In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker
when a fault is detected. The first protective relays were electromagnetic devices, relying on
coils operating on moving parts to provide detection of abnormal operating conditions such as
overcurrent, overvoltage, reverse power flow, over-frequency, and under frequency.
Electromechanical protective relays operate by either magnetic attraction, or magnetic
induction.
Fig 13 - Relay Panel
21

29. Types of relay :-
Over voltage relays
Over current relays
I.D.M.T. Relay
Direction relay
Differential relay
Buchholz’s relay
22

30. Over Voltage Relay
 A relay that has contacts that operates when a set voltage is exceeded to provide an alarm
or to trigger a breaker.
Over current Relay
 Over current relay is a type of protective relay which operates when the load current
exceeds a pickup value.
IDMT Relay
 IDMT relay is inverse definite minimum time relay. It is one in which Time of operation
is inversely proportional to magnitude of fault current near pickup value and becomes
substantially constant slightly above the pickup value of the Relay.
Directional relay :
 Directional over current relays respond to excessive current flow in a particular direction
in the power system. It is used for protection in d-c power circuits.
Differential relay:
 The differential relay is one that operates when there is a difference between two or more
similar electrical quantities exceeds a predetermined value.
Buchholz’s relay:
 Buchholz relay is a safety device mounted on some oil-filled power transformer and
reactors, equipped with an external overhead oil reservoir called a "conservator".
23

31. INSULATOR
An insulator also called a dielectric is a material that resists the flow of electric current.
Insulators are used in electrical equipment to support and separate electrical conductors
without allowing current through themselves.
Types of insulators:-
1. Pin type
2. Suspension type
3. Strain type
4. Shackle type
5. Stay type
Fig 15 - Insulator
24

32. WAVE TRAPPER
 Wave trap is a device used in the substation at the incoming line
 Wave trap is also called as line trap.
 The wave trap extracts the high frequency information from the power line and route it to
the telecomm panels.
On the basis of blocking frequency bank, the wave trap can be following type:
1. SINGAL FREQUENCY
2. DOUBLE FREQUENCY
3. BROAD BAND
Fig 16 - Wave-Trap
25

33. BUS BAR
 Bus Bars are the common electrical component through which a large no of feeders
operating at same voltage have to be connected.
 A bus bar is a conducting bar that carries heavy currents to supply several electric circuits.
 Bus bars are made up of copper rod or thin walled tubes.
Fig 17 - Bus Bar
26

34. BATTERY ROOM
There is a battery sexton or battery room which has 55 batteries of 2 volt each for 132KV
section and 110 batteries for 220KV section. Therefore D.C. power available is for
functioning of the control panels. A battery charger to charge the battery.
Various parts of lead acid batteries:
 Plates
 Separators
 Electrolyte
 Container
 Terminal port  Vent plugs
Charging of batteries:
Initial charging
It is the first charging given to batteries by which the positive plates are converted to
"leadperoxide", whereas the-ve plates will convert to spongy lead.
Also in a fully charged battery the electrolyte specific gravity will be at its highest venue or
1.2 and its terminal voltage will be 24 volts
Discharging-
When a fully charged battery delivers its energy out by meeting a load the lead peroxide of
the +ve plates slowly gets converted to lead sulphate and the spongy lead of the -ve plates
also gets converted into lead sulphate during this time the specific gravity of the electrolyte
also decreases the value around 1.00 and the terminal voltage also decreases from its initial to
a lower value which may be around 1.85 or 1.8.
27

35. Fig 18 - Battery Room
28

36. MEGGER INSULATING TESTER
A Megohmmeter or insulation resistance tester is a special type of ohmmeter used to
measure the electrical resistance of insulators. Insulating components, for example cable
jackets, must be tested for their insulation strength at the time of commissioning and as part
of maintenance of high voltage electrical equipment and installations.
29

37. MULTIMETER
A multimeter is a measuring instrument that can measure multiple electrical properties. A
typical multimeter can measure voltage, resistance, and current, in which case it is also
known as a volt-ohm-milliammeter (VOM), as the unit is equipped with voltmeter, ammeter,
and ohmmeter functionality. Some feature the measurement of additional properties such as
temperature and capacitance.
30

38. CLOSING COIL
The closing coil is an electrical accessory used for controlling the closing of the power
contacts of the circuit breaker. The springs of the circuit breaker are to be loaded before the
action of the closing coils. It is controlled by NO contact.
31

39. Chaper-4
CONCLUSION
Now I have studied a lot a about the electrical transmission system. One must have never
thought that so many things are required for just switching on a television or a refrigerator or
say an electrical trimmer .The three wing of Electrical system viz. generation, transmission,
distribution are interconnected to each other and that too perfectly .Here man and electricity
work as if they are a family Lots of labour, capital and infrastructure is involved in the system
just to have a single phase, 220V, 50HZ power supply at our houses. Thank you so much
again for staff of 220KV GSS KOTPUTLI.
Future Scope:
JE(Junior Engineer in electrical department)
SSE(Senior section engineer) in electrical department
32

40. Chapter-5
REFERENCES
1. Instruction manual of instruction transformer (TELK instrument transformer) provided
byU.P.P.T.CL.
2. A Text- book of ELECTRICAL TECHNOLOGY (AC and DC machines) by B.L.
Theraja.
3. A Text- book of POWER SYSTEM by V.K Mehta.
4. Electrical Power System by C.L. WADHWA.
33