Three-phase grid-connected inverter anti-islanding detection method

The invention discloses a three-phase grid-connected inverter anti-islanding detection method. By setting a relation characteristic curve between the frequency of reactive current and the frequency of power grid side voltage, reactive current disturbance is superposed on a current inner ring set value to obtain a new inner ring reactive current set value, and the advantages that influences on the electric energy quality are small, the island detection time is short, the disturbance direction is self-adaptive, and the slope of the disturbance equation is self-adaptive are achieved. According to specific configuration, the corresponding disturbance quantity is calculated by a disturbance rule calculating module, then, the corresponding disturbance quantity is superposed on the reactive current inner ring set value, and therefore island detection of a three-phase grid-connected inverter based on a power grid side feedback current and power grid side voltage frequency characteristic curve can be achieved, and the grid-connected inverter meets the national standard grid connection requirement of inverters.