Table 2. 1998 Canadian Electric Utility Reliability Performance SOURCE: Ontario Hydro, May 1, 1998.

An electric power substation is a facility that provides a junction between parts of the power grid. The substation's functions, critical for the proper operation of the power system, include the interconnection of power lines from different parts of the system; the monitoring and control of system operating conditions; and the protection of the power system equipment.

Classification and General Description

Substations may be classified into one of several categories depending on their location and function within the system. Generator substations are located at the site of power generating stations and provide the connection to the transmission system. Bulk power substations link the transmission system to the subtransmission system, stepping the voltage down through a transformer (transformer substation), or linking high-voltage transmission lines from different parts of the system without changing the voltage (switching...