An improved control scheme for a standalone DFIG with unbalanced and nonlinear loads using proportional-resonant controllers

This paper proposes an improved control scheme to regulate the stator voltage in a standalone doubly fed induction generator (DFIG) under nonlinear and unbalanced loads. The proposed control scheme uses proportional resonant controllers in the 2-phase stationary frame of reference with a zero sequence controller to compensate the voltage distortion under unbalanced loads. It is demonstrated that the proposed control scheme achieves better performance over existing control methods. The total harmonic distortion (THD) of the stator voltage is significantly improved over conventional control methods. Simulation results presented show the effectiveness of the scheme.