Direct current circuit breaker of mixed switching device

Abstract

The invention provides a direct current circuit breaker of a mixed switching device. The direct current circuit breaker consists of a first mechanical switch (K1), a first capacitor (C1), a second capacitor (C2), a third capacitor (C3), a first full-controlled switch device (S1), a second full-controlled switch device (S2), a third full-controlled switch device (S3), a fourth full-controlled switch device (S4), a fifth full-controlled switch device (S5), a sixth full-controlled switch device (S6), a seventh full-controlled switch device (S7), an eighth full-controlled switch device (S8), a first half-controlled switch device (T1), a second half-controlled switch device (T2) and a first light arrester (Z1). By controlling turning on and turning off of the full-controlled switch devices and the half-controlled switch devices, rapid turning on and turning off of fault current of a direct current power grid are achieved.

Description

Technical field

[0001] The invention relates to a circuit breaker, in particular to a DC circuit breaker. Background technique

[0002] The damping of the DC system is low. Compared with the AC system, the control and protection of the DC system is more difficult. And for the flexible DC transmission system based on fully controlled semiconductor devices, the device has a weak overcurrent withstand capability, and the fault current may exceed the maximum withstand value of the device within a few milliseconds, causing damage to key devices and even the entire converter station. Therefore, it is necessary to quickly limit and cut off the fault current in order to maintain the safe and stable operation of the DC grid and protect the key equipment in the grid. High-voltage DC circuit breakers become effective or even the only devices that quickly limit and cut off fault currents. Since the DC current has no natural zero crossing point, the DC arc is not easy to extinguish. None o...

Images