A Novel Islanding Detection Method for Photovoltaic Grid Connected System

Abstract

It is very important to detect islanding effect timely and accurately in the case of power grid failure. Therefore, a new periodic perturbation positive feedback active frequency drift method is proposed in this paper. When the power grid fails, the inverter output voltage frequency always has obvious change under the different load of inverter, and the islanding effect can be detected quickly and accurately by this control method. Experimental results show that the proposed method can detect grid faults quickly and accurately under different load conditions.