Torque Ripple Reduction of Permanent Magnet Synchronous Machine Drives with Tangential Vibration Acceleration Control

Torque ripple reduction by harmonic current injection for permanent magnet synchronous machine (PMSM) drives has been widely investigated. The existing research can be briefly divided into feedforward-based methods and feedback-based methods. Feedforward-based methods require torque ripple model and machine parameters, so that the performance of those methods is limited due to the accuracy of the model itself and machine parameters. Feedback-based-methods are presented to improve the performance of torque ripple reduction, which are mostly based on speed harmonics caused by the corresponding torque ripples, while the speed operation range of feedback-based-methods is limited due to the fact that speed harmonics will be filtered by the inertia of the drive systems at high speeds. Therefore, it is required to propose one torque ripple reduction method without machine parameters, which also avoids the limitation of the speed operation. In this paper, a novel feedback-based torque ripple reduction method for PMSM drives is proposed, wherein quadrature magnitudes of tangential vibration acceleration of the stator are measured and regulated by the model-free adaptive controller (MFAC) for torque ripple reduction, since the tangential force that generates torque ripples will also act on the stator and generate tangential vibration. The proposed controller can generate optimal harmonic current references without speed limitations and any machine parameters. The proposed method is evaluated by experiments and is verified to reduce torque ripples of PMSM drives effectively.