Modeling and Suppression of Torque Ripple in PMSM Based on the General Airgap Field Modulation Theory

The permanent magnet synchronous motor is the most commonly used motor in servo systems. Torque ripple caused by the variation of the airgap magnetic field limits the steady-state performance of the servo system. In this article, a novel torque ripple model is established based on the general airgap field modulation theory. A compound control algorithm based on the current feedforward algorithm is proposed to suppress the torque ripple caused by the field modulation behavior. Finite element analysis simulation is conducted to verify the effectiveness of the proposed torque ripple model. Experimental results on a prototype machine show that the proposed torque ripple model is valid and the proposed control algorithm can effectively reduce the torque ripple and improve the steady-state performance of the servo system at medium or high speed.