Characterization of AC Solid State Circuit Breaker Based on SiC MOSFET Device

This paper is about the characterization of AC solid-state circuit breakers. Firstly, an AC solid state circuit breaker topology based on SiC MOSFETs in reverse cascade is proposed. Due to the limitation of the rated current of a single SiC MOSFET, it is necessary to connect them in parallel to increase the through-current capability. However, during the parallel connection process, the current between the branches may differ greatly due to the difference of the devices themselves as well as the differences in the line stray parameters. In order to analyze the mechanism of this problem and the measures to solve it, the influence of line stray inductance is next explored from the perspectives of static current sharing and dynamic current sharing. The method of using coupled inductors for current equalization is verified. Finally, the losses of different AC solid-state circuit breaker topologies are analyzed.