Torque Ripple Suppression for Standalone Brushless Doubly-Fed Induction Generator-DC System Based on Power Winding Harmonic Current Control

The brushless doubly-fed induction generator-dc (BDFIG-DC) system has received more and more attentions with the cost-effective and efficient topology in recent years. However, it suffers from the torque ripple due to the distorted flux and current caused by the diode rectifier, which reduces the mechanical reliability of the system. In order to address this issue, this article proposes a torque ripple suppression method based on the power winding (PW) harmonic current control. Compared with the traditional method, the proposed method takes the sixth and twelfth harmonic components of the torque generated by the fifth and seventh harmonic fluxes and currents into account, which can maximize the torque ripple suppression effect of all the controllable PW harmonic currents. Besides, it is with the simpler control algorithm and higher robustness. Comprehensive experimental results based on a 5-kVA BDFIG demonstrate the effectiveness of the proposed method.