DC-link fault current limiter-based fault ride-through scheme for inverter-based distributed generation

Owing to increasing the penetration level of the inverter-based distributed generations (IBDGs) in power systems, their fault ride-through (FRT) capability has become one of the essential issues of new grid codes. This study proposes a novel DC-link fault current limiter (DLFCL)-based FRT scheme to improve the FRT capability in IBDG units. The DLFCL module has almost no effect on normal operation of IBDG. When a short-circuit fault occurs in power system, the DLFCL module effectively limits the inverter output current and protects its switching devices. The employed DLFCL does not need any control, measurement and gate driving system. Also, it has simple configuration and it is not mandatory to use a superconductor inductor in its power circuit so, it has low initial cost. By using the proposed scheme, it is possible to provide continues operation of IBDG even at zero grid voltage. Analytical analysis is presented in details. The effectiveness of the proposed approach is approved through extensive simulation studies in PSCAD/EMTDC environment. An experimental setup is used to verify the main concept of the proposed approach.