Comparing Schemes to Mitigate the Effect of Symmetrical Grid Voltage Sags on the Operation of a Double-Fed Induction Generator

To lessen the negative impact of symmetrical voltage sag on the performance of a grid-connected wind-driven double-fed induction generator (WD-DFIG), four methods are suggested in this study. Adding RL impedance to the stator winding, adding RL impedance to the rotor winding, adding RL impedances to the stator and rotor windings simultaneously, and adding a passive filter to the stator windings are the four methods. At two voltage sag values at sub-sync and super-sync speeds, the response of the stator current, rotor current, rotor voltage, dc link current, dc link voltage, and electromagnetic torque under each suggested technique is compared at sub-sync & super-sync speeds.