A Multi-Port Solid State Circuit Breaker for LVDC Protection: Towards A Lossless Design

Solid state circuit breakers (SSCBs) offer a promising solution for direct current (dc) system protection thanks to its ultrafast fault interruption speed, up to 100 times faster than conventional mechanical circuit breakers. SSCBs also provide enhanced safety, featuring arc-less fault current interruption and intelligent functionalities, such as status monitoring, communication, etc. However, large conduction losses in SSCBs remain a significant challenge, resulting in reduced efficiency and necessitating bulky, heavy cooling systems. In this article, a novel high-efficiency multiport SSCB (M-SSCB) for low voltage direct current (LVDC) and medium voltage direct current (MVDC) applications that significantly reduces conduction losses compared to conventional SSCBs is proposed. The operating principles and advantages of the proposed M-SSCB, particularly its ability to minimize power losses, are thoroughly analyzed. The feasibility and effectiveness of the design are demonstrated through a SiC mosfet-based hardware prototype. The results show that the proposed SSCB is an ideal protection solution for dc systems with multiple connected sources and loads.