Abstract:

Compared with the mechanical circuit breakers,the solid-state circuit breakers have been widely focused for their advantages such as the faster breaking speed and higher lifetime.A low-voltage DC solid-state circuit breaker topology and operating principle based on SiC devices is introduced,and the technical difficulties of solid-state circuit breakers are analyzed,including the low-inductance package and device design,the isolated switch technology and the fast fault identification technology.A prototype of ±375 V DC solid-state circuit breaker is developed and tested for the fault current breaking and the temperature rise.The results show that the DC solid-state circuit breaker can achieve 1 kA short-circuit current breaking within a hundred microseconds.In addition,the prototype is equipped with the functions such as the fast fault identification,the programmable protection curve,the external communication and the remote control.

Key words: solid-state circuit breaker, SiC device, device packaging, fast fault identification