Research on asymmetrical faults ride-through control of Doubly Fed Induction Generator (DFIG)

Based on the effect of the asymmetric grid voltage on DFIG and the positive and negative sequence mathematical model of DFIG, this paper analyses the composition of output active and reactive power of the DFIG stator and the generator electromagnetic torque under asymmetrical grid-voltage condition. Considering the effect on stator side active and reactive power, electromagnetic torque, and DC side voltage caused by the negative sequence current, a current positive sequence component tracking control strategy is proposed, and the positive and negative sequence components of grid voltage are processed separately both in the rotor side converter control and the grid side converter control. Hysteretic positive sequence current tracking control technology is applied to the rotor side converter, which achieves a current non-poor tracking. Current feedforward control technology is introduced into the inner ring of grid side inverter control, which ensures that negative sequence current is zero, while the outer ring