Simulation and Experimental Verification of Inrush Mitigation and Fault Detection in Inverter-Based Microgrids

Microgrids (MGs) have attracted attention for their ability to enhance power-supply resilience; however, they face several challenges, among which fault detection is a critical issue from the perspective of human safety. Faults can be classified into short circuits and earth faults. The magnitude of the earth-fault current is determined by the ground voltage, fault resistance, presence of an earth-voltage transformer (EVT), and system capacitance. Owing to the operational characteristics of MGs, the disconnection of the EVT and a reduction in system capacitance are likely to occur, making earth-fault detection difficult. Connecting the EVT and line-to-ground capacitors to the main source within the MG is considered an effective solution.