The 11 kV transmission lines. These lines play a crucial role in the power distribution network. Here are some key points:
1. Voltage Level:
o An 11 kV distribution line carries electricity at 11 kilovolts (kV).
o It serves to distribute power to homes and businesses within areas equipped with medium-voltage networks.
o These lines can be either underground or overhead.
2. Substation Configuration:
o A typical 11 kV substation consists of various components:
Power Transformer: Steps down the voltage from the high-voltage transmission line to the lower voltage used by the distribution system.
Circuit Breakers: Ensure safe operation by interrupting the flow of current when necessary.
Disconnect Switches: Used for isolating specific sections of the network.
Busbars: Conductors that connect various components within the substation.
Meters: Measure electrical parameters for monitoring and billing purposes.
3. Reliability and Redundancy:
o To enhance reliability, substations often have a double busbar system.
o This system includes a main busbar and a spare busbar.
o Incoming lines can connect to either busbar using bus-couplers.
o If one busbar requires maintenance, the load can be seamlessly transferred to the other busbar.
4. Step-Down Transformers:
o Incoming 66 kV supply is stepped down to 11 kV using 3-phase transformers.
o Typically, one transformer handles the entire substation load, while the other acts as a standby unit.
o Both transformers can share the load if needed.
5. Outgoing Lines:
o The 11 kV outgoing lines feed distribution substations near consumer localities.
o Circuit breakers with isolators connect both incoming and outgoing lines.