Evaluation of CS-MCT in DC Solid-State Circuit Breaker Applications

DC solid-state circuit breakers (SSCB) have attracted much attention in recent years owing to the rise of a new dc application field such as dc microgrids based on distributed generation systems. However, due to the inherent large on-state resistance of power semiconductor devices, the proliferation of SSCB is impeded by a large energy loss and finite fault current interruption capability. Compared with commonly used power devices, metal-oxide-semiconductor (MOS)-controlled thyristor (MCT) features an ultralow on-state resistance high surge current capability, which could be a potential candidate for SSCB applications. In this paper, an evaluation of cathode-short MCT (CS-MCT) in a 400 V dc SSCB is presented by using both physical-based mixed-mode simulation and experimental measurements. Corresponding results show the SSCB based on CS-MCT attains a 30% reduction in energy loss compared with that using insulated gate bipolar transistor (IGBT) and the fault current interruption capability of SSCB can be enhanced by suppressing the mistriggering of CS-MCT. The excellent device performances coupled with inherent reliability of solid-state power switch make CS-MCT a good candidate for future dc SSCB applications.