Research on breaking capacity of hybrid circuit breaker based on vacuum interrupter and SF6 interrupter in series

Hybrid circuit breaker, consisting of a vacuum interrupter and an SF₆ interrupter connected in series, which takes the place of SF₆ circuit breaker, is a kind of high-voltage big-capacity circuit breaker for Low-carbon technology research area. The experimental model of fiber-controlled hybrid circuit breaker with a vacuum circuit breaker and an SF₆ circuit breaker in series was set up, and the fault current interruption experiment was conducted on two circuit breakers in different collaborative action moments. The voltage distribution between the vacuum circuit breaker and SF₆ circuit breaker was analyzed, the characteristics and interactions between vacuum arc and SF₆ arc were studied during the interruption process. The experimental results indicate that the vacuum circuit breaker makes up the shortage of low dielectric recovery speed of SF₆ interrupter in the initial period of dielectric strength recovery, whereas the SF₆ circuit breaker takes the advantage of high voltage endurance of SF₆ and withstands larger parts of the transient recovery voltage in the peak period of dielectric recovery voltage. The breaking capacity of hybrid circuit breaker is bigger than SF₆ circuit breaker.