Electrical substations in electrical power system can be find in power plants (for stepping up the voltage for transmission of power to long distances), switching stations where power can be transmitted in desired manner during transmission and distribution centers where the power is stepped down and provide power to the house hold and commercial terminals. Hence Electrical substation plays an important role and can be find in different locations of the power system ( generation centers to distribution centers). Substations can be assumed as a nodal point in the power system where different conductors coming from different places connects together to a point and on the other hand different conducting lines travel out to different locations in the power system.
Electrical substations are different types:
Air Insulated Substations:
In this subtatation where all the substation equipment are exposed to environment or the all the substation equipment stands outside in the open air. This type of substation has advantage of cheap in cost and disadvantage of all the equipment ( bus bars, insulators ) expose to the external atmosphere susceptible to fault and life of equipment decreases.
Gas Insulated Substations:
This type of substations are completely enclosed in sF6 gas modules. This substation takes very little place (1/8 th of Air Insulated Substation). This has the advantage of more reliable and disadvantage of high cost and difficult to operate if fault occurs.