Definition and function

Definition: An on-off station refers to a power supply and distribution facility used to receive and distribute electricity, and is usually referred to as a switching station in a high-voltage grid. It is the most basic unit at the bottom of the distribution network, and it is also one of the key links of power transmission from high voltage to low voltage.

Function: The opening and closing office mainly solves the problem of insufficient number of outgoing distribution cabinet in high voltage substation and reduces the number of lines in the same path. It is equivalent to the extension of the substation bus bar, and can be used to solve the problem of limited inlet and outlet line spacing or limited inlet and outlet line corridor in the substation, and play the role of power support in the region.

Second, structure and composition

The opening and closing station is mainly composed of primary part, secondary part, transformer, low voltage (electricity consumed), background monitoring system, grounding network, etc.

The primary part includes the bus bar, circuit breaker, isolation switch and other equipment in the high voltage switch cabinet, which is used to introduce the high voltage line into the opening and closing office, and distribute the feed line in different operating modes.

The secondary part includes the circuits of measurement, control, signal, protection and automatic device, which is used to realize the monitoring and protection of the power system.

Third, characteristics and applications

Characteristics: The characteristics of the on-off station are that the voltage on the incoming line side and the outgoing line side of the power supply is the same, and there is no change in voltage level.

Application: The open and close station in the medium voltage power grid is generally used for the acceptance and distribution of 10kV power, and the distribution device is equipped with the medium voltage distribution inlet and outlet lines to redistribute the power. In the railway power system, the opening and closing station is also used for the control place to ensure the safe and reliable power supply of electric traction when the traction network has branches.