Research on Fault Ride-Through Technology of Wind Turbines

With the advancement of the "dual carbon" goal, wind power generation has become the core support for China"s energy structure transformation. The grid-connected operation of large-scale wind farms has put forward higher requirements for the safety and stability of the power system. Fault ride-through capability, as a key indicator to measure the grid-connected performance of wind turbines, directly determines the survival ability of wind farms and the continuity of system power supply when grid faults occur. Aiming at the problem of wind turbine off-grid under grid faults (including doubly-fed induction generators (DFIG) and permanent magnet synchronous generators (PMSG)), this paper systematically carries out research on fault ride-through technology. Firstly, it sorts out the types of grid faults and the mechanism of their impact on wind turbines, and analyzes the fault response characteristics of different types of wind turbines; secondly, it summarizes the classification, working principles and application limitations of existing fault ride-through technologies, focusing on the advantages and disadvantages of mainstream technologies such as crowbar circuits, energy storage support, and virtual synchronous machine control; then, aiming at the problems of lagging response and poor suppression effect of traditional fault ride-through technologies under extreme conditions such as deep low-voltage drop and high-voltage impact, an improved fault ride-through strategy integrating adaptive crowbar and energy storage coordination is designed. By dynamically adjusting the crowbar input timing and energy storage charge-discharge power, the power balance and voltage support of the unit during faults are realized; finally, a simulation platform is built based on MATLAB/Simulink, and simulation verification is carried out under different fault types and fault depth conditions. The research results show that the proposed improved strategy can effectively suppress rotor overcurrent and DC bus overvoltage during faults, shorten the fault recovery time, improve the ride-through capability of the unit under extreme fault conditions, and provide theoretical support and technical reference for the engineering application of wind turbine fault ride-through technology.