Anti-islanding control of grid-connected photovoltaic inverter based on positive feedback frequency drift

The anti-islanding control of the PV grid-connected inverter has long been a concern of both utilities and generating equipment owners because of the potential for safety hazards and equipment damage. So the islanding effect must be prevented in the application of the grid-connected PV system .In this paper, the theory of passive and active islanding detection methods is analyzed and compared. Then, according to the two kinds of conventional methods and the control course of grid-connected inverter, this paper proposes a new anti-islanding control method namely the positive feedback frequency drift, designs the anti-islanding inverter test circuit according to the IEEE Std. 2000-929 and tests the anti-islanding function of the inverter. The test result shows that the positive feedback frequency drift is feasible and up to the demand of IEEE Std. 2000-929.