Inductance-simulating control for DFIG-based wind turbine to ride-through grid faults
For doubly fed induction generator (DFIG)-based wind turbine (WT), large electromotive force will be induced in the rotor circuit under grid faults, and the rotor side of DFIG is prone to suffering from overcurrent and overvoltage. To mitigate this problem, an inductance-simulating control strategy is proposed to enhance its low-voltage ride through (LVRT) capability. In this method, the rotor side converter (RSC) is controlled to simulating as an inductance. Furthermore, under proper inductance value, both the required rotor voltage and post-fault rotor current can be reduced within the permissible range. In addition, the electromagnetic torque ripple can be effectively eliminated. Finally, the simulation and experimental results clearly demonstrate the effectiveness of the proposed method.