An electrical substation is a supplementary station of an electricity generation, transmission and distribution system where voltage is transformed from the high to low or the overturn utilizing transformers. Electric power might flow through several substations between generating plant and customer, and may be changed in voltage in several steps.
A substation which has a step-up transformer enhances the voltage whilst decreasing the current, as a step-down transformer decreases the voltage whilst increasing the current for commercial and domestic distribution. The term, substation comes from the days prior the distribution system became a grid.
The first substations were linked to only one power station where the generator was placed, and were subsidiaries of that power station.
Machinery in substation
Substations usually have switching, control and protection equipment and one or more transformers. In a huge substation, circuit breakers are used for interrupting any overload currents or short-circuit which might occur on the network. Smaller distribution stations might use fuses or re-closer circuit breakers for protecting distribution circuits. Electric Substations do not, by and large, have generators, though a power plant might have a substation close at hand.
Other equipment, like; voltage regulators and power factor correction capacitors might also be situated at a substation
High-rise buildings might have quite a lot of indoor substations. Indoor substations are generally found in urban areas for reducing the noise from the transformers, for reasons of manifestation, or for protecting switchgear from the extreme climate or pollution situations.
Where a substation has a metallic barrier, it must be suitably grounded or earthed for protecting the people from high voltages which might occur throughout a fault in the network. Earth faults at a substation could cause a ground probable rise. Currents flowing in the Earth’s surface all through a fault could cause metal objects for having a considerably different voltage than the ground under the person’s feet; this touch probability presents a danger of electrocution.