电网对称故障下双馈风力发电机低电压过渡鲁棒控制策略

With respect to different voltage drop resulting from grid faults, a robust control strategy on small voltage drop is proposed in order to preserve the rotor current in the safety margin and meet the requirements of the grid code for low voltage ride-through by adopting the designed control strategy without activating crowbar. Firstly based on the analysis for the electromagnetism transient process after voltage drop, control-oriented mathematical model is described for the DFIG wind power system. A rotor excitation controller is designed by utilizing nonlinear robust control technology, which can guarantee the rotor current in the transient process remains in the margin and the static value of the rotor current converges to the desired value under sudden grid voltage drop and variable wind speed, uncertain parameters and external disturbances. Simulation validations and comparisons with conventional PID controller are given.