Research on Detection Technology of Islanding Effect in the Photovoltaic Grid-Connected Power Generation System

The islanding effect is one of the main problems caused by photovoltaic grid-connected power generation technology. Currently, most photovoltaic power plants use active frequency offset detection methods to detect islanding effects. Still, this method interferes with the output power quality, but its detection efficiency is greatly affected by the load. In this paper, the drawbacks of the active frequency offset detection method are improved to obtain the positive feedback operational frequency offset detection method. A simulation model of a single-phase photovoltaic grid-connected system is built based on MATLAB software, and islanding detection is simulated for the two detection schemes. The islanding effect under different conditions is detected by adjusting the parameter settings such as load. Comparing the simulation results before and after the improvement, it is proved that the detection efficiency of the improved scheme is higher.