An Integrated Control and Protection Scheme Based on FBSM-MMC Active Current Limiting Strategy for DC Distribution Network

DC faults can easily lead to overcurrent in dc distribution networks; these pose serious threats the safe operation of system. The blocking a modular multilevel converter based on full-bridge submodule (FBSM-MMC) is mostly utilized cut off fault current. However, causes short-term blackouts entire network, and there are presently no effective solutions address this problem. In study, an integrated control protection scheme FBSM-MMC active current limiting strategy proposed. project includes three stages: first, MMC used limit output about 1.2 p.u. after occurrence (Stage 1); second, faulty lines identified asynchronous zero-crossing features currents two ends line 2); finally, isolation cooperation converters, circuit breakers, high-speed switches proposed isolate 3). network restart quickly via converters. Finally, simulation four-terminal flexible PSCAD/EMTDC demonstrates effectiveness scheme.