Study on Load Rejection Overvoltage of DFIG-Based Wind Power Transmission System

Wind turbines are normally connected to the power grid through long transmission lines. When load rejection occurs on the grid side, it may cause overvoltage at the end of the line, which may threaten the power equipment. Wind turbines utilize power electronics-based interfaces for grid interconnection and power injection. The rapid response of these power electronic devices results in distinct load rejection overvoltage characteristics compared to traditional power systems. The conventional analysis method for overvoltage of traditional power system is no longer applicable. In this paper, the generation mechanism and influencing factors of power frequency overvoltage under load rejection conditions are analyzed for wind power generation system based on doubly fed induction generator (DFIG). The validity of the analysis is verified through electromagnetic transient simulations conducted on PSCAD simulation platform.