Novel Active Islanding Detection Method for Distributed Power Generation System

A novel active islanding detection method for a distributed power generation system is proposed in this paper. The distributed power generation system includes a DC power source and a grid-connected power converter. The grid-connected power converter acts as a virtual inductor as the frequency is slightly higher than the fundamental frequency of utility voltage. The distributed power generation system can only supply power to the load as the utility power interruption occurs. At this instant, the load voltage will be changed in amplitude or frequency due to the operation of virtual inductor. Hence, the proposed method can immediately detect the islanding operation.