Improved vector control of DFIG based wind turbine during grid dips and swells

This paper presents a novel vector control strategy for the doubly-fed induction generator (DFIG) based wind turbine during grid voltage dips or swells. The transient electromagnetic process of the DFIG during the grid fault is discussed in detail. An improved control scheme with the dynamic process of stator excitation current variation taking into account is presented. Besides, the main magnetic flux saturation effects are also considered in order to make the model congruous to a practical wind turbine system. Simulation results of the DFIG system under symmetrical low and high grid voltage fault show that the suggested improved vector control is capable of effectively inhibiting the fundamental frequency component of the rotor current from damaging the rotor-side excitation inverter and improving the uninterrupted operation capability of DFIG based wind power generation system during grid dip/swell fault.