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Operation and Maintenance of a 220/132KV Substation
As in the case of 132KV Substation, the single line diagram (SLD) shall show: lightning arrestor, C.T/P.T unit, isolators, protection and metering P.T. and C.T. circuit breakers, again isolators and circuit breakers, main power transformer, all protective devices/relays and other special equipment like CVT, GUARD RINGS, etc. as per design criteria.
The major stations include a control room from which operations are coordinated. Smaller distribution substations follow the same principle of receiving power at higher voltage on one side and sending out a number of distribution feeders at lower voltage on the other, but they serve a more limited local area and are generally unstaffed.
The central component of the substation is the transformer, as it provides the effective in enface between the high- and low-voltage parts of the system.