Fault Detection Method for DG Disconnection in Inverter-Interfaced Microgrids with Photovoltaic System

Due to the growing use of photovoltaic (PV) systems in distribution networks and sensitivity of these systems to high current caused by faults, it is crucial to quickly detect the occurrence of a fault in the network and protect the PV system. This paper proposes a method that uses the direct-axis current component (id) and its rate of change, which is one of the control parameters of the PV system, to detect faults in less than a half cycle. For this purpose, the PV system is precisely modeled in PSCAD/EMTDC software. To verify the performance of the proposed method, various simulations are performed by considering load variations, irradiation fluctuations and various types of faults. The results show the effectiveness of the method both in distinguishing load variations and irradiation fluctuations from faults as well as fault detection.