Design Improvement of Fault Current Limiter Based on HSCR and Fast Switch Considering the Impact of Internal Ground Fault

Based on high coupled split reactor (HCSR) and fast switch, the fault current limiter (FCL) can effectively limit the fault current, thereby solving the problem of excessive short-circuit current in the development of the power grid. In this paper, the principle, structure, and validation of the FCL are analyzed, and the impact of the internal ground fault on the FCL is studied. Besides, two improving schemes for the wiring mode and the current-transformer (CT) configuration are proposed. From the results, the original configuration may cause the problem that the fault current of the single-arm is too large, which exceeds the breaking capacity of the fast switch and causes its damage. Both improving schemes can better overcome this problem to improve the reliability of the FCL.