High current medium voltage solid state circuit breaker using paralleled 15kV SiC ETO

The SiC ETO concept, developed based on the SiC gate turn-off (GTO) thyristors, has the advantages of simple voltage controlled gate drive, very high blocking voltage, low forward voltage drop and large turn-off current capability, demonstrating a high suitableness for medium voltage solid state circuit breaker applications. In this paper, a 15 kV/200 A solid state circuit breaker (SSCB), which is suitable for medium voltage direct current (MVDC) power systems protection, is designed and developed based on the parallel and high temperature operation of the 15 kV SiC emitter turn-off (ETO) thyristors. To realize the 200A current rating, three SiC ETOs are connected in parallel. The static and dynamic current sharing of the SSCB is tested at 4.5kV/200A, showing it is an ideal candidate for the medium voltage SSCB applications.