Active and Reactive Power Control of DFIG for Wind Energy Conversion under Unbalanced Grid Voltage

In this paper, a novel control method for smoothening the stator active or reactive power ripple components under unbalanced grid voltage for wind power generation using doubly-fed induction generators (DFIG) is proposed. The negative sequence component of the rotor current is used to reduce the active and reactive power ripples, which is extracted by band pass filters. It is shown that reducing the reactive power ripples results in the torque ripple reduction. Simulation results using PSCAD show the proposed control algorithm can reduce the active or reactive power ripple components as well as reducing the torque and speed ripples