Development of 24kV-rated High Speed Circuit Breaker

Abstract

We have developed a 24kV-20kA-1200A-rated High Speed Circuit Breaker with a new electromagnetic repulsion mechanism for both open and close operations. The new operating mechanism has a opening fixed coil, a closing fixed coil and a movable coil housed in a metal coil case. Driving efficiency of new operating mechanism is achieved about two times larger than that of a conventional repulsion mechanism consisted of a fixed coil and a copper repulsion plate. The 24kV High speed Circuit Breaker can open contacts within about 1ms from a trip signal and break current within one cycle, and close contacts within about 10ms. In a short circuit current interrupting test, this circuit breaker interrupted the current with a peak value of 50kA successfully.