Paralleled SiC MOSFETs DC Circuit Breaker with SiC MPS Diode as Avalanche Voltage Clamping

This paper proposes a solid-state DC circuit breaker composed of SiC MOSFETs and a SiC diode, based on the principle of avalanche voltage clamping. To realize a solid-state DC circuit breaker, it is necessary to reduce the conduction loss and increase the breaking capability. A parallel connection of power semiconductor devices is the most suitable configuration that can meet these requirements. However, in such a configuration, the current balance during current interruption may be affected by the difference in the breakdown voltage characteristics of the power semiconductor devices. The proposed solid-state DC circuit breaker is clamped using a SiC merged pin Schottky diode with high avalanche tolerance and robust characteristics under repetitive avalanche events. Experimental results from an unclamped inductive switching test circuit with a 400-V DC distribution system show that the proposed solid-state DC circuit breaker can interrupt currents up to 50-A.