A Control Method for Grid-forming Inverters to Suppress Overcurrent at Grid Fault Clearance

Grid-forming inverters (GFMs), operating as voltage sources, are prone to overcurrents during grid disturbances such as ground faults. Although multi-loop GFM inverters can effectively suppress overcurrents during ground faults, overcurrents still occur at the moment of fault clearing. This paper proposes and verifies a control method for a dq-based multi-loop GFM to mitigate overcurrents arising at fault clearing under ground fault conditions. Simulation results obtained using MATLAB/Simulink demonstrate that the proposed method successfully suppresses overcurrents both during faults and at fault clearing.