Survey of photovoltaic power systems islanding detection methods

Distributed generators (DG), such as photovoltaic cells, are low cost, highly reliable and have electronic interfaces and reduced emissions. Even with the mentioned benefits, there are technical limits on the degree to which DG can be connected. One of these technical concerns is the islanding phenomenon. In utility practice at the present time, accidental islanding is an undesirable mode of operation and is not permitted. Therefore, islanding must be detected and the islanded DG units must be disconnected from the rest of the system. This paper presents a survey of the islanding detection methods for grid-connected photovoltaic (PV) systems.