Direct current breaker for disconnecting fault current, control system and control method

Abstract

The invention discloses a direct current breaker for disconnecting a fault current. The direct current breaker comprises a main current circuit and a transfer current circuit which are connected in parallel, wherein the main current circuit comprises one or more tandem high-speed mechanical switches; and the transfer current circuit comprises a magnetic coupling transfer module and a solid-state switch circuit which are connected in series. The invention further discloses a control system and method for disconnecting the fault current. According to the direct current breaker, the system and the method, the rapid disconnection of the current can be realized, the volume of the current breaker is effectively reduced, and the manufacturing cost of the current breaker is effectively lowered; and by virtue of the magnetic coupling transfer module, the rapid transfer of the current is realized, the isolation between a secondary charging circuit and a main loop is realized, the transfer speedis high, and the disconnection reliability is high; and meanwhile, a follow current circuit is connected with the high-speed mechanical switches in parallel, so that the disconnection failure caused due to the restriking of a connection hole after the breakage of the current breaker is avoided, and the disconnection reliability is further improved.

Description

technical field [0001] The invention belongs to the technical field of electrical equipment, and in particular relates to a DC circuit breaker, a control system and a method for breaking fault currents. Background technique [0002] The hybrid circuit breaker composed of high-speed mechanical switches and power semiconductor devices has the advantages of large current capacity, fast shutdown speed, and strong current limiting capability, and has become a research hotspot in the field of large-capacity system breaking. Compared with other hybrid solutions, the hybrid DC circuit breaker scheme using power semiconductor devices with full control function to break current has the advantages of faster breaking speed and more favorable breaking rated current. However, when using a fully-controlled power semiconductor device to break current, it is usually necessary to connect the fully-controlled power semiconductor device in series with a mechanical switch to realize current tran...

AI Technical Summary

Problems solved by technology

[0003] After the traditional DC circuit breaker is broken, the mechanical switch needs to withstand the shutdown voltage. Due to the insufficient recovery of the dielectric strength of the mechanical fracture medium, heavy breakdown is prone to occur and cause breaking failure.

[0004] The capacitor charging circuit in the traditional transfer current circuit is directly connected to the main circuit without isolation, the charging power supply and the main circuit will interfere during the disconnection process, and the withstand voltage requirements for the main circuit charging power supply are very high, and the disconnection is unreliable

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