A SEMINAR PRESENTATION

ON 220 KV GSS UDAIPUR

SUBMITTED TO:- SUBMITTED BY :-

Rajasthan Rajya Vidyut Prasaran Nigam Limited(RVPN) has been established under companies Act 1956 by Govt. of Rajasthan and registered with Registrar of Companies as "RAJASTHAN RAJYA VIDYUT PRASARAN NIGAM LIMITED" of 2000-2001with its Registered Office at VIDYUT BHAWAN, JYOTI NAGAR, JAIPUR.The granted RVPN a license for transmission and bulk supply and RVPN has discharging its function as a Transmission and Bulk Supply License in the State.

ABOUT R.R.V.P.N.L

Construction and Maintenance of EHV lines and Grid Sub-stations

SLDC operation.Sharing of power from jointly owned

projects

The main functions carried out by RVPN :-

LAYOUT OF GSS

Isolater Wave trap Bus bar Lightning Arrester Circuit breaker Power Transformer Instrument Transformer Potential Transformer C.T. Buchholz Relay Earthing Power Line Carrier Communication (PLCC)

EQUIPMENTS OF SUB STATION

Isolators are designed to open a ckt under no load. Its main purpose is to isolate portion of ckt from the other & is not intended to be opened while current is flowing in the line.

There are two types of isolators:- off load isolators on load isolators

ISOLATERS :

DIAGRAM OF ISOLATOR

Wave Trap:-

• To prevent high frequency signals from entering other zones.

DEFINITION:- A bus bar is a conducting bar that carries heavy currents to supply several electric circuits. Bus bars are copper rod or thin walled tubes and operate at constant voltage.

TYPES OF BUSBARS:- Main busbar Auxiliary busbar One busbar is main busbar & another is spare or

auxilary busbar.

BUSBARS

Lightning Arrester :-

• To discharge lightning over voltages and switching over voltages to earth.

A circuit breaker is a piece of equipment which can:- break a ckt automatically under fault conditions. make a ckt either manually or by remote control under fault

conditions.

PRINCIPLE:- A ckt breaker essentially consists of fixed & moving contacts, called electrodes under normal operating conditions, these contacts remain closed & will not open automatically until & unless the systems becomes faulty. When a fault occurs on any part of the system, the trip coils of the breaker get energised & the moving contacts are pulled apart by some mechanism.

CIRCUIT BREAKER & CLASSIFICATIONS

oil circuit breakers Sulphur Hexa Fluoride circuit breakers Air-Blast circuit breakers vaccum circuit breakers Under training SF6 type, vaccum ckt

breaker & Air-Blast ckt breakers were used in the GSS.

CLASSIFICATION:-

Transformer is an electrical machine which works on the principle of electromagnetic induction. It transfers electric power from one electric ckt to other with the help magnetic path(flux) on constant frequency but equal or different current voltages. For this purpose two sets of insulated windings are wounded on a close terminated steel core. The winding which is connected to the supply is called primary winding & that winding is connected to the load is called secondary winding.

POWER TRANSFORMERS

MAIN PARTS OF POWER TRANSFORMERS:-

• Core• Winding(H.V winding, L.V winding, tertiary

winding)• Tap changer• Tank • Conservator• Buchholz relay• Dehydrating breather• Oil temperature indicator• Winding temperature indicator

POWER TRANSFORMER PICTURE

Instrument transformers are used for measurement and protective applications together with equipments such as meters & relays.

The lines in a station are operated at high voltages and carry currents of thousands of amperes. The measuring and protective devices are designed for low voltage generally 100v and currents about 5A, therefore they will not work satisfactory if mounted on the power lines. This difficulty can be overcome by using instrument transformers, which will step down the voltages and currents to the convenient level for the operation of measuring instruments & relays.

INSTRUMENT TRANSFORMERS

POTENTIAL TRANSFORMERS

Potential transformers are instrument transformers. They have a large number of secondary turns and a fewer number of primary turns. They are used to increase the range of voltmeters in electrical substations and generating stations.

These are also called as voltage transformers used for line and circuit protections.

DIAGRAM OF PT’s

Current transformer is used for measurement of alternating electric current.

The objective of C.T. is :- Reduce the scale of the metering scale. Insulated the measuring instrument

from voltage.• Used for protective system

Current transformer

DIAGRAM OF CT’s

Definition:- Buchholz relay is a gas actuated relay. It can only be fitted to the transformers equipped with conservator tanks as it is installed in b/w the conservator tank and the main tank i.e., the pipe connecting the two.

Principle:- Whenever a fault occurs inside the transformers, the oil of the tank gets overheated and gases are generated.

The heat generated by the high local current causes the transformer oil to decompose and produce gas which can be used to detect the faults.

BUCHHOLZ RELAY

DIAGRAM OF BUCHHOLZ REALY

Connection of an electric equipment to the earth with the help of connecting rod or wire of negligible resistance is known as earthing.

Methods of earthing arrangements at 220kv GSS:

pipe earthing plate earthing

EARTHING

For exchange of data’s and transfer message between grid substation voice communication is necessary for this purpose high frequency carrier current is transmitted on same transmission line on which power is transmitted.

Hence such communication is called “power line communication

POWER LINE CARRIER COMMUNICATION PICTURE

Conclusion.

Design of sub station involves a number of complexities and detailed engineering.

A judicious approach in tackling various problems is required on the part of design engineers as well as the suppliers of various equipments so as to achieve trouble free operation of power system.

Thank you