Dynamic behavior of photovoltaic single-phase inverter following faults in medium-voltage networks using CRIEPI´s power system simulator

The reverse power flow at distribution transformers caused by the large-scale integration of residential photovoltaics (PVs) might prevent the clearance of high-voltage transmission system faults within the designated time. The time to stoppage of PVs following short-circuit faults and the type of protective relays to stop PVs following single-line-to-ground faults were studied with a 66kV-emulated 1650V transmission line of the test system to examine the dynamic behavior of PVs following faults. All PVs stopped within two seconds following faults. The test results showed that the anti-islanding protection relays operated first when the pre-fault power flow in the 1650V transmission line was nearly zero, while the fault clearance protective relays led by the instantaneous overvoltage relay operated first when the pre-fault power flow in the same line was apart from zero. The maximum PV current was 130% of its rated current.