Method of Single Phase Photovoltaic Grid-connected System Islanding Detection Based on Power Disturbance

Photovoltaic power generation systems usually apply inverters as the bridge to realize grid connection with power system,and in order to ensure the safety and stability of the power network,anti-islanding detection has become one of the most important techniques for photovoltaic grid-connection.Based on analyzing traditional passive and active islanding detection methods,a new method of compound islanding detection based on the photovoltaic inverter output disturbance is proposed to overcome the frequently disturbed shortcomings in traditional methods.With technical specifications of IEEE Std.2000-929 and UL1741,the working mechanism,threshold setting and realization were described.Simulation analysis proves that the method can achieve rapid island detection when the matching degree of the output power of the inverter with the load consumed power is high,without non-detection zone and harmonic pollution.