A Novel Multi-Port Solid-State Circuit Breaker Concept With Integrated Energy Absorbing Branch

Solid-state circuit breakers (SSCBs) have been widely used to achieve actively and high-efficiency turn off. However, the conduction losses and costs may significantly increase when the SSCBs are used in multiport system. In this article, a new multiport SSCB (M-SSCB) concept is proposed for direct current (dc) microgrids. The energy absorbing branches (EABs) are integrated into one, thus the required number of devices can be reduced by at least half compared with typical separate bidirectional SSCB topologies in the same voltage and current level applications. Moreover, by introducing the grounded EAB based on a thyristor, the leakage current is eliminated from the system and the fault current is bypassed. This further increases the allowable dc voltage and safety of the breaker. As a result, the M-SSCB has a more economic design, smaller volume and higher safety. The operation principles and designing guidelines are presented in detail. The feasibility and effectiveness are verified based on experimental results and comparative analysis.