Harmonics Rejection in Stand-Alone Doubly-Fed Induction Generators With Nonlinear Loads

This letter proposes a novel method to reject 6n ± 1 harmonics in the stator voltage at the point of common coupling (PCC) for a stand-alone doubly-fed induction generator (DFIG) supplying a balanced three-phase diode rectifier. These harmonics are rejected by using the rotor current controller in the fundamental synchronous reference frame. The proposed control algorithm is based on a proportional integral controller and a bank of resonant filters. In this frame, each resonant filter in the rotor current controller has the possibility of rejecting one pair of the positive and the negative stator harmonic voltages at the PCC. Experimental results with 2.2-kW DFIG are shown in this letter.