Improvement of the stand-alone DFIG performance feeding nonlinear and unbalanced loads using active and reactive power theory

This paper proposes new and simple control method for a stand-alone doubly fed induction generator (DFIG) connected to unbalanced and nonlinear loads. This type of load causes harmonic distortion in the stator current and voltage. To solve this problem, a novel control method is proposed in the load side converter (LSC). In this method, instantaneous active and reactive power theory in stationary [α-β] frame is used. Unlike other control strategies, which needs to extract and compensate each harmonic or unbalanced component individually, in this paper, all harmonics and unbalanced components are injected by LSC. Finally, stator voltage becomes sinusoidal with very fast dynamic response. The performance of the DFIG feeding nonlinear and unbalanced loads is evaluated for steady state and dynamic conditions, using MATLAB/Simulink.