Methods for Suppressing Neutral Point Displacement Voltage in Power Distribution Networks

Imbalances in the three-phase-to-ground parameters of the power distribution network can generate unbalanced three-phase voltages, compensated through the introduction of electrical current into the neutral point to counter the asymmetrical currents caused by the line-to-ground parameter imbalances. Commonly used current control methods rely on precise measurements of ground parameters and harmonic currents, which is impractical. In response, a dual closed-loop proportional-integral control method for suppressing overvoltage in three-phase unbalanced power distribution networks has been designed. This method allows for the suppression of unbalanced overvoltage without the need to measure ground parameters through dual closed-loop control, thereby enhancing the suppression effect. Finally, the feasibility of the proposed control method is verified through simulation analysis.