A Novel Three-Phase Unbalanced Overvoltage Suppression Method for Distribution Network

Aiming at suppressing three-phase unbalanced overvoltage in distribution network, a new suppression method was proposed in this paper. The PWM active inverter is used to inject a current with the amplitude and phase easily obtained into the neutral point of distribution network. The optimal injection current only need to record the amplitude and phase of the neutral point voltage at the initial moment of the three-phase unbalance, and takes it as a reference. After injecting the optimal injection current, the neutral point voltage can be suppressed to 0, i.e., the purpose of three-phase unbalanced overvoltage suppression can be achieved. Simulation analysis showed that it has the fast response, and it can effectively suppress the three-phase unbalanced overvoltage, which verified the feasibility and validity of the proposed method.