Technology

Substations can be classified into three main types based on their function and voltage levels:

Step-Up Transmission Substations

• Located near power plants
• Transform generated voltage (11-25kV) to high transmission voltages (220-765kV)
• Enable efficient long-distance power transmission
• Include transformers, switchgear, and protection equipment

Step-Down Transmission Substations

• Transform high voltage to sub-transmission levels (69-138kV)
• Located at intermediate points in the transmission network
• Connect transmission lines to regional distribution systems
• Include circuit breakers and switching equipment

Distribution Substations

• Transform sub-transmission voltage to distribution voltage (4-35kV)
• Located near load centers
• Supply power to local distribution networks
• Include distribution transformers and protection devices
• Feed residential, commercial and small industrial loads

Each type contains essential equipment like transformers, circuit breakers, switches, bus systems, and protective relays to ensure reliable power delivery while maintaining system stability and safety.