Harmonic compensation for variable speed DFIG wind turbines using multiple reference frame theory

This paper proposes novel methods to compensate the grid current harmonics by controlling the back to back converter of dual-fed induction generator (DFIG). The selected low-order harmonics is detected and calculated by a multiple reference frame harmonics estimator. The control methods of how to regulate the harmonics are developed for both the gridside converter (GSC) and the rotor-side converter (RSC) of the back to back converter attached to the DFIG. The harmonics regulator control for GSC and RSC are parallel with the main decoupled control of the back to back converter operating the DFIG wind turbine system to generate electrical power to grid. Matlab/Simulink is employed to investigate the performance of proposed methods.