Current-limiting circuit breaker high-speed contact drive mechanism

Abstract

The invention discloses a high-speed vacuum DC current-limiting circuit breaker, comprising a high-speed vacuum contact mechanism for quickly opening when receiving an external command, and a reverse current generating circuit for producing a current zero-crossing point in a vacuum interrupter , a freewheeling circuit used to obtain zero voltage recovery time after the current of the vacuum interrupter crosses zero, and an energy absorption circuit used to absorb circuit energy, the high-speed vacuum contact mechanism, reverse current generation circuit, freewheeling circuit connected in parallel with the energy absorption circuit. The invention has the advantages of strong current limiting ability, rapid action, reliable shutdown and the like.

Description

technical field [0001] The invention relates to a high-speed contact mechanism of a current-limiting circuit breaker, in particular to a high-speed contact driving mechanism of a hybrid current-limiting circuit breaker based on the combined drive of a high-speed electromagnetic repulsion mechanism and a permanent magnet mechanism. Background technique [0002] The hybrid current-limiting circuit breaker uses mechanical contacts connected in parallel with power electronic switches to break the current. In order to limit the fault current and reduce the breaking pressure of the power electronic switch, the mechanical contacts are required to be able to operate within a few hundred microseconds after a short-circuit fault occurs. Internally, the moving and static contacts can be separated quickly, and when an overvoltage occurs at both ends of the contact, a large enough contact opening distance can be formed to prevent the contact gap from being broken down and reignited. [0...

AI Technical Summary

Problems solved by technology

The electromagnetic repulsion mechanism uses the pulse electromagnetic force generated by the pulse induction magnetic field to push the contacts to move at high speed. Due to the low efficiency of the electromagnetic repulsion mechanism, usually below 5%-10%, in order to achieve the rated contact opening distance, a huge initial energy is required. At the same time, due to the high movement speed of the contacts, the impact on the mechanism is large, which may easily lead to problems such as unreliable locking after opening and short mechanical life of the mechanism.

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