Three-phase unbalanced voltage suppression method for distribution network

The invention discloses a three-phase unbalanced voltage suppression method for a distribution network. The suppression method comprises the following step of: controlling the inverter circuit by using a composite control method in parallel connection of a double loop control and a repetitive control; measuring the three-phase voltage of the distribution network and the displacement voltage of a neutral point in real time; when the voltage of the displacement voltage of the neutral point is greater than three percent of the nominal phase-phase voltage, determining the distribution network in athree-phase voltage unbalanced state, and outputting a zero-sequence current by the inverter circuit; injecting the zero-sequence current into the neutral point of the distribution network and adjusting the zero-sequence current, so that the displacement voltage of the neutral point is zero. The three-phase unbalanced voltage suppression method for the distribution network provided by the invention is capable of effectiv