Investigation on breaking characteristic of hybrid DC switch for DC micro-grid

DC micro-grid is a future direction with the development of the distributed generation. The DC circuit breaker which is used for short-circuit protection is urgent need. The research and development of hybrid DC circuit breaker which is used in DC micro grid fast protection is one of the key technologies that affect its development. The prototype of hybrid DC breaker whose rated voltage and breaking current is 400V and 10kA respectively is designed and the control system is designed by the STM32 controller. By this way, we made a prototype hybrid DC breaker, whose breaking current is 10kA, closing time is 200μs, and opening time is less than 2ms based on the closing test and fault tripping test. It is proved that the prototype of the developed hybrid DC circuit breaker has the advantages of fast tripping action, strong ability to limit arc, good action consistency and so on. Moreover, it verifies the validity of the prototype design and the accuracy of the current transfer characteristics under different parameters, which provides a reasonable basis and reference for the design of the Hybrid DC circuit breaker in the future.