An Accurate Harmonic Current Suppression Strategy for DC-Biased Vernier Reluctance Machines Based on Adaptive Notch Filter

This article proposes an accurate harmonic current suppression strategy for direct current (dc)-biased VRMs based on adaptive notch filter (ANF) to reduce torque ripple and power loss. A new harmonic reference frame is proposed in dq-axis and combined with ANF, thus harmonic currents are accurately extracted and analyzed. Furthermore, a phase-shift strategy is proposed for dc-biased VRMs, realizing precise compensation of harmonic voltages. The proposed ANF-based harmonic currents suppression strategy has a better performance in harmonic suppression and dynamic response and is suitable for a wider speed range in comparison with traditional harmonic suppression control strategy. What is more, the parameter design of the proposed method is easier compared with traditional method. Finally, the conclusions are verified by experimental results.