Harmonics Mitigation of Standalone Brushless Doubly-Fed Induction Generator Feeding Nonlinear Loads Considering Power Converter Voltage Rating

In standalone brushless doubly-fed induction generator (BDFIG) power generation systems, nonlinear loads would cause the distorted power winding (PW) voltage, which mainly includes the fifth and seventh voltage harmonics. In order to mitigate the harmonic voltage, this paper proposes an improved coordinated control method considering the power converter voltage rating. Based on the principle of maximum harmonics mitigation per voltage for different order harmonics, the proposed control method is not only applied to the machine-side converter (MSC) for eliminating the seventh PW harmonic voltage, but also to the load-side converter (LSC) for rejecting the fifth harmonic. A proportional integral plus a resonant controller (PIR) is employed to the current control loops in both MSC and LSC so as to obtain a good current track ability. Comprehensive experimental results with 30 kVA BDFIG are presented to verify the proposed method.