New AC solid-state ciruit breaker with simple charging and rebreaking capabilites

Recently there have been widespread used distributed generators and sensitive loads. It enables solid-state circuit breaker (SSCB) an imperative device to get acceptable power quality of AC power grid systems. The existing AC SSCB composed of SCRs requires some auxiliary mechanical devices to achieve the reclosing operation before fault recovery. But the new AC SSCB can achieve the quick breaking operation and then be reclosed with no auxiliary mechanical devices even under sustained short-circuit fault. Furthermore, the proposed AC SSCB can be applied regardless of neutral point grounded method of 3-phase power source, and also all the commutation capacitors are charged naturally without any complex control of main thyristors and auxiliary ones. The performance features of the proposed AC SSCB are verified through simulations of the short-circuit faults. The proposed AC SSCB is expected to be widely used to design and realize a lot of AC grid systems.