Comprehensive fault ride-through scheme for doubly-fed induction generators

With the growth of wind energy penetration in electricity transmission grids, fault ride-through (FRT) ability is required in order to maintain the uninterrupted operation of wind farm in voltage disturbance scenarios. For widespread used doubly-fed induction generator FRT issues, an auxiliary hardware circuit is adopted in large-grid-voltage drop situations. Among all hardware protection devices, the rotor crowbar scheme can suppress rotor overcurrent immediately, while the stator series impedance scheme has the advantage of increasing voltage during voltage dips. A comprehensive FRT scheme based on series impedance and rotor crowbar is proposed. Also, the simulation results show that the proposed method can keep the continuous operation of wind farm during fault situation and recovery, also suppress the overcurrent during voltage recovery and improve the terminal voltage.