Diode Clamped Solid-State Circuit Breaker: A Novel Solid-State Circuit Breaker without Dynamic Voltage Unbalancing Issues

In this paper, a new solid-state circuit breaker for medium voltage applications is proposed named Diode Clamped Solid-State Circuit Breaker (SSCB). Unlike the conventional medium-voltage SSCBs using simultaneously operated switches in series to block medium level voltage, Diode Clamped SSCB utilizes a novel diode clamped topology to extend its operating voltage. In the breaking process, the switches in the Diode Clamped SSCB are tripped sequentially to interrupt fault current and do not incur dynamic voltage unbalancing issues. After the breaking operation, the voltage across the switches is clamped to the capacitor voltage. In addition, with asymmetric configuration, Diode Clamped SSCB can effectively limit the increase of fault current and reduce the volume of metal oxide varistors (MOVs). PLECS simulation software as well as an experimental prototype have been used to prove the plausibility and superiority of the Diode Clamped SSCB.