An active frequency drift islanding detection method for photovoltaic microgrid

Abstract

Islanding detection is a necessary function of photovoltaic microgrid system. When islanding occurs, it is required to quickly detect the islanding state, cut off the islanding power at the same time, and minimize the loss of microgrid. In view of the low detection efficiency of the traditional active frequency offset method in the islanding detection of inverter, a positive feedback active frequency offset method is proposed in this paper. This method perturbs the frequency from both positive and negative directions, which effectively solves the problem of low detection efficiency. The simulation results further verify the effectiveness of this method: it can not only quickly detect the island state and shorten the detection time, but also further reduce the blind area of island detection and improve the efficiency of island detection.