A PRESENTATION ONSUMMER TRAINING AT 220 KV

G.S.S., HINDAUN CITY

Submitted byRohitashav Goyal

Branch : EEEReg. No.-110106002

INTRODUCTION

The "220 KV.GSS, RVPN Ltd. is ideally located at the HINDAUNCITY. GSS is the medium of connection between generating stationand consumers (Traction, Industrial & Domestic etc.) by providingsafety and reliability of whole system in case of fault.

Steps of this sub- station are :- to step down the incoming voltage ofpower transmission to a required value i.e. 220 KV to 132 KV, 132 KVto 33KV and then supply to consumer's feeders of GSS done byconnecting auto-transformer. Operation requirement of variousequipment have been included in detailed manner further in report.There are 3 incoming line from 2 different sub-station. One line of220KV coming from DAUSA(Lilo sikraye), second line of 220 KVcoming from GUDAPOLE and third line from 400KV GSSHINDAUN.

132 KV AND 33KV OUTGOING FEEDERS

• There are two different outgoing traction line of 132kv for railways,

next we have six 132kv outgoing feeder namely :

• 1.132 kv Todabhim

• 2.132 kv Shri Mahaveer Ji

• 3.132 kv Gangapur

• 4.132 kv Karauli

• 5.132 kv Weir

• 6.132 kv Baseri

33 kv outgoing feeders

• 1. 33 kv Gudapole

• 2. 33 kv RICCO(R)

• 3. 33 kv Mahu

• 4. 33 kv Khera

• 5. 33 kv RICCO(I)

• 6. 33 kv Jat Ki Saray

• 7. 33 kv Hindaun

• 8. 33 kv Suroth

WHAT IS A SUBSTATION?

• In India electrical power is generated at avoltage of 11KV to 33 KV which is stepped upto the transmission level in the range of 66 KVto 400 KV, This voltage level is stepped downagain in the range of 220 KV to 220 VOLT. Fortransmitting power member of transmissionand switching have to be created. These areknown as “SUB STATION”.

IMPORTANT INSTRUMENTS AT A SUBSTATION

• Main bus and auxiliary bus

• Insulsators

• Protective Relays

• Circuit Breaker

• Isolators

• Power Transformers

• Current Transformers

• Potential Transformers

• Lightning Arresters

• Relay and metering panels

Shunt capacitors and shunt

reactors

• Bus Coupler

• On Load Tap Changer

BUS BARS

• At 220 kv gss Hindaun city we have 2 main busbars of 220kv main bus-1 and main bus2 ,alsowe have one auxiliary bus bar of 220 kv incase of failure of one of the bus bar it cansupply power hence increasing the reliabilityof the system , apart from 220 kv bus bar wehave one main bus bar of 132 kv namely mainbus 1 and auxiliary bus of 132kv.

CONDUCTORS

• Various voltage levels and the suitable conductors used for them at the 220 kv GSS are mentioned below:

• 220 kV Main Bus : Quadruple / Twin ACSR Zebra / Twin AAC Tarantulla • 220 kV Auxiliary Bus : ACSR Zebra • 220 kV equipment interconnection : Twin ACSR Zebra / Single ACSR Zebra • 220 kV overhead bus & droppers in all bays : Twin ACSR Zebra / Single

ACSR Zebra • 132 kV Main Bus : ACSR Zebra • 132 kV Auxiliary Bus : ACSR Panther • 132 kV equipment inter connection : ACSR Zebra / ACSR Panther • 132 kV overhead bus & droppers in all bays : ACSR Panther • 33 kV Main Bus ACSR Zebra • 33 kV Auxiliary Bus ACSR Zebra

INSULATORS

• The insulator for the overhead lines providesinsulation to the power conductors from theground so that currents from conductors do notflow to earth through supports.

• These insulators are generally made of glazedporcelain or toughened glass. Insulators arezigzag in shape to reduce the current flow.Diameter of the insulators are decided accordingto the voltage level.

PROTECTIVE RELAYS

Primary purpose of a relay is to detect the fault and take

the necessary action to minimize the damage to the

equipment or to the system

CIRCUIT BREAKER

• During a fault, the zone which includes the faulted apparatus is de-energized and disconnected from the system. In addition to its protective function, a circuit breaker is also used for circuit switching under normal conditions. The main function of a circuit breaker is to quench the arc as soon as possible in case of a fault. At 220 kv gss we have sf6 circuit breaker(ABB).

Circuit Breaker

ISOLATORS

• “Isolator" is one, which can break and make an electric circuit in no load condition. These are normally used in various circuits for the purposes of Isolation of a certain portion when required for maintenance.

They are capable of:

• Interrupting transformer magnetized currents

• Interrupting line charging current

• Load transfer switching

ISOLATORS

POWER TRANSFORMER

• Distribution transformers reduce the voltage of the primary circuit to the voltage required bycustomers. This voltage varies and is usually:

• 120/240 volts single phase for residential customers• 480Y/277 or 208Y/120 for commercial or light industry customers.• We have three transformers of total capacity 250 MVA namely:

• Specifications:

• 1. BHEL transformer of 50 MVA capacity and 220/132kv• 2. GEC transformer of 100 MVA capacity and 220/132kv• 3. TELK transformer of 100 MVA capacity and 220/132kv.

• Along with these transformers of 220/132 kv we have three more transformers of 132/33 kvcapacity namely:

• 1. IMP transformer of 25 MVA capacity• 2. GEC transformer of 25 MVA capacity• 3. BHEL transformer of 12.5 MVA capacity

CT

• As you all know this is the device which provides the pre-decoded fraction of the primary current passing through the line/bus main circuit. Such as primary current 60A, 75A, 150A, 240A, 300A, 400A, to the secondary output of 1A to 5A

PT

• A potential transformer (PT) is used to transform the high voltage of apower line to a lower value, which is in the range of an ac voltmeter or thepotential coil of an ac voltmeter.

CVT

• Capacitive voltage transformer is being used more and more for voltagemeasurement in high voltage transmission network, particularly forsystems voltage of 132KV and above where it becomes increasingly moreeconomical. It enables measurement of the line to earth voltage to bemade with simultaneous provision for carrier frequency coupling, whichhas reached wide application in modern high voltage network for telemetering remote control and telephone communication purpose

L.A.

• A lightning arrester (in Europe: surge arrester) is a device used on power systems and telecommunications systems to protect the insulation and conductors of the system from the damaging effects 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.

• SpecificationsManufacture: English electric company

• No. of phase: One • Rated voltage: 360 kV • Nominal discharge current: (8×20μs) 10 kA • High current impulse: (4× 100μs) 100 kA • Long distribution rating: (200μs) 500 kA

LIGHTNING ARRESTER

CONTROL PANEL

• Control panel contain meters, control switches and recorders located in the control building. These are used to control the substation equipment to send power from one circuit to another or to open or to shut down circuits when needed. It is the brain of the GSS.

OLTC

• In this method a number of tapings are provided on the secondary of the transformer. The voltage drop in the line is supplied by changing the secondary emf of the transformer through the adjustment of its number of turns by using transition resistor which is placed in between each tapping

EARTHING

Earthing is the provision of a surface under the sub station, which has a uniform potential as nearly as zero or equal to Absolute Earth potential. The provision of an earthing system for an electric system is necessary by the following reason.

1. In the event of over voltage on the system due to lighting discharge or other system fault. These parts of equipment which are normally dead as for as voltage, are concerned do not attain dangerously high potential.

2. In a three phase, circuit the neutral of the system is earthed in order to stabilize the potential of circuit with respect to earth.The earthing is of two principal types :-· Neutral Earthing· Equipment Body Earthing

BATTERY ROOM

• We have a battery room which has 55 batteries of 2.3 to 2.5 volt each for 132KV section and 110 batteries for 220KV section. Therefore D.C. power available is for functioning of the control panels.

FAULT OPERATION

• Relay trips as fault is detected in the system.

• Breaker operates

• Alarm at control room blows up

• Alarm is manually reset

• If the fault persists , isolator is removed

• If no local fault present , then fault feeder is contacted

• Relay is reset

• Supply is resumed after fault removal

Maintenance of GSS

Daily jobs

• Visual checking of any hotspot

• Checking of air and gas leakage from the breaker

• Taking readings from the control panels of 220 kv and 132 kv

• Checking of oil level from CT and CVT

Transformer maintenance

• Permission from SLDC

• Switching load to other transformer

• CB is operated

• Isolators are operated

• Earthing is provided to remove the residual charge due to induction

SLD OF 220 KV GSS , HINDAUN CITY

THANK YOU