Stationary frame control scheme for a stand-alone doubly fed induction generator system with effective harmonic voltages rejection

A novel stationary frame control scheme for harmonic voltages rejection in a stand-alone doubly fed induction generator (DFIG) with non-linear loads is proposed in this study. The distortion in the stator output voltage of the stand-alone DFIG is mainly because of the non-linear voltage drop in the internal impedance of the generator caused by the non-linear load current. The proposed control scheme directly regulates the instantaneous rotor current in the rotor-side converter (RSC) to reject the fifth and seventh harmonics in the stator output voltage at the point of common coupling (PCC). The main contribution of this study is the development of a novel reference rotor current generator implemented in the stationary reference frame. In this frame, the rotor current controller is developed based on a proportional and three resonant regulators (P3R) that is capable of directly regulating the fundamental, fifth and seventh components of rotor currents without involving decompositions of sequential components. Simulations and experimental results with a 2.2 kW DFIG supplying non-linear loads are presented to demonstrate advanced features of the proposed control scheme.