4kV/400A/1.6MW Wireless Coupled Solid-State Circuit Breaker with Modular Active Voltage Clamping and Resonant Current Injection Circuits

This paper presents design, evaluation, and testing of a 4kV/400A/1.6MW solid-state circuit breaker (SSCB) with modular active voltage clamping and resonant current injection circuits for emerging medium-voltage direct-current (MVDC) power distribution systems. There are three major contributions in this paper. First, from total configuration point of view, the 4kV/400A/1.6MW SSCB prototype is built up by 40 functionally consistent power electronics submodules, which indicates complete modularity and flexibility. Second, a 225W high efficiency wireless power converter with multiple 1-to-1 units is developed to provide high isolation strength for the MVDC SSCB auxiliary power supply system. Third, the proposed SSCB main branch features an active voltage clamping based hard-switching and resonant current injection based soft-switching combined dual tripping capability, which provides operation flexibility in practical MVDC systems. A 4kV/2kA interruption testing is conducted on the SSCB prototype operating at hard switching mode, validating a high fault current capability with ultrafast response speed. Then a 4kV/400A zero current switching (ZCS) soft turn-off interruption testing is conducted, indicating reduced power loss of main switches. A 400A/1hour current conduction test is conducted on the complete prototype, which validates a high efficiency of 99.96% at thermal stead state.