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1. Definition of sub -station:-
The assembly of apparatus used to change some characteristics (e.g. Voltage ac to dc freq. p.f. etc) of electric supply is called sub-station.
2. Introduction: -
The present day electrical power system is a.c. i.e. electric power is generated, transmitted and distributed in the form of Alternating current. The electric power is produce at the power station, which are located at favorable places, generally quite away from the consumers. It is delivered to the consumer
through a large network of transmission and distribution. At
many place in the line of power system, it may be desirable and necessary to change some characteristic (e.g. Voltage, ac to dc
frequency p.f. etc.) of electric supply. This is accomplished by suitable apparatus called sub-station for example, generation voltage (11KV or 6.6KV) at the power station is stepped up to high voltage (Say 220KV to 132KV) for transmission of electric power. Similarly near the consumer’s localities, the voltage may have to be stepped down to utilization level. This job is again accomplished by suitable apparatus called sub-station.
2 .1About the substation :-
The substation in bhankrota, Jaipur, Rajasthan is one of the power grids in the state of Rajasthan.
The most important of any substation is the grounding
(EarthingSystem) of the instruments, transformers etc. used in the substation for the safety of the operation personnel as well as for proper system operation and performance of the protective devices.
An earthes system comprising of an earthing mat buried at a suitable depth below ground and supplemented with ground rods at suitable points is provided in the substations. These ground the extra high voltage to the ground. As it is dangerous to us to go near the instrument without proper earth. If the instruments are not ground properly they may give a huge shock to anyone who would stay near it and also it is dangerous for the costly instrument as they may get damaged by this high voltage.