Behaviour of grid-connected photovoltaic inverters in islanding operation

The behaviour of photovoltaic (PV) inverters operating in islanding mode is very complicated. The islanding of PV inverters depends on the anti-islanding protection system. Therefore, this paper first investigates different methods for the islanding detection of PV inverters. Different factors influencing the behaviour of PV inverters in the islanding operation, such as the behaviour of load, parameters in PV inverter control system, are also studied by simulations. Two kinds of PV systems connected to LV and MV network are concerned by a deeper study. An evaluation of different passive methods is carried out for different scenarios in order to verify their performances. Experimental tests in the islanding operation are carried out for PV inverters connected to the LV network.