Submitted to: Submitted by: Practical training seminar 400KV G.S.S. BIKANER Submitted to: Submitted by:

INTRODUCTION As the formation of Rajasthan in April,1949 there were 15 state owned power houses with a total installed capacity of 13271 KW and an aggregate maximum demand on the stations of approximately 7483 KW. Rajasthan Rajya Vidyut Utpadan Nigam Ltd. is the transmission company and three regional distribution companies namely Jaipur Vidyut Vitaran Nigam Ltd., Ajmer Vidyut Vitaran Nigam Ltd. And Jodhpur Vidyut Vitaran Ltd. Are under it. The transmission company will own and operates all the 400KV, 220KV,132KV and 66KV electricity lines and system in state and also responsible for producing power as per demand.

CONTENTS GENERAL DISCUSSION ON SUB STATIONS FEEDERS TRANSFORMERS CIRCUIT BREAKERS PT CT RELAY LA WAVE TRAP ISOLATER

Various Incoming And Outgoing Lines :- 400KV incoming line from Suratgarh. 220KV outgoing and incoming line from Bikaner 1. 220KV outgoing feeders : 3.1. Bikaner 1 3.2. Bikaner 2 3.3. Nagaur 3.4. Dungargarh

Single line diagram of 400 kv GSS, Bikaner:-

TRANSFORMER A Transformer is a device that :- It is a mutual link in power system. Which makes possible to low voltage to be step up to the extra high voltage for long distance transmission and then transferred to voltage for utilization at proper load centre. A Transformer is a device that :- Transfer electric power from one circuit to another. It does so without change of frequency. It accomplishes this by electromagnetic induction. Types of transformer:- Step-up Step-down

TRANSFORMER It is a device that transfers electrical energy from one circuit to another circuit through the medium of magnetic field without a change in frequency.

TRANSFORMER COOLING Types of cooling:- Cooling is necessary for the power transformers to moderate their efficiency and to avoid malfunctioning Types of cooling:- Natural cooling Air cooling Forced oil coiling Water cooling

CIRCUIT BREAKERS They are used to operate on the fault either on line or with transformer, depending upon where it is connected. This isolates the faulty line or equipments from the live portion of the substation by opening automatically through protective relay, control cables etc, in a definite time.

Main types of Circuit Breaker :- 1. Air circuit breaker 2. Air blast circuit breaker 3. Oil circuit breaker 4. SF6 circuit breaker

C. T. & P.T. CT:- PT:- STEPING DOWN VOLTAGE STEPING DOWN CURRENT FOR MEASURMENT PT:- STEPING DOWN VOLTAGE FOR PURPOSE OF PROTECTION

RELAY:- A relay is a device that detects the fault & initiates the operation of the circuit breaker to isolate the defective element from the rest of the system. It detects the abnormal conditions by costantly measuring the electrical quantities (voltage, current, frequency & phase angle) which are different under normal & fault conditions.

Types Of Relays :- Over voltage relays. Over current relays. Earth fault relays. Directional relays. Differential relays. Buchholz’s relays.

LIGHTNING ARRESTOR Lighting arrestor is a device which protects the overhead lines and other electrical apparatus viz, transformer from overhead voltages and lighting.

Types of Lightning Arrester:- Rod Gap arrester Horn gap arrester Multi gap arrester Expulsion type LA Valve type LA Silicon Carbide Arrestors Metal Oxide Arrestors

INSULATOR In order to avoid current leakage to the earth, through the supporting structure provided to the overhead transmission lines, insulator are used. Insulator are similar in function to other insulator used in sub station and transmission poles and towers. As insulators should have following characteristics : High insulation resistance. High mechanical strength. No internal impurity or crack disc. Generally Porcelain or Glass is used as material for insulator. Porcelain because of its low cost is more common.

Insulator

WAVE TRAP It is used to prevent high frequency signals from entering other zones.     Line trap shall be inserted into high voltage transmission line to prevent undue loss of carrier signal for all power system conditions.

ISOLATORS Isolators which are also called disconnect switches or air break switches after the assembly as per drawings on the leveled structures the adjustment of connecting pipes, moving and fixed contacts is done so that all the three phase of the isolator close and open simultaneously and there is a full surface contact between moving and fixed contacts.