Generalized Modeling and Torque Ripple Analysis in PMSM Drives With Nonsinusoidal Back‐EMF

Permanent magnet synchronous motors (PMSMs) are a constant presence in a large number of applications. In many cases, PMSMs can present nonsinusoidal back electromotive force (back‐EMF), which results in torque ripple when conventional field‐oriented control (FOC) is applied. However, the analytical description of torque ripple sources in nonsinusoidal PMSM is not commonly addressed in the literature. In this context, this work proposes a generalized model of PMSMs with nonsinusoidal back‐EMF, analyzing the interaction with stator currents in both and frames, while considering the effects of th‐order harmonics. The derived expressions allows for modeling torque ripple, demonstrating how the presence of back‐EMF and stator current harmonics, and alignment error impact on the electromagnetic torque. Furthermore, a current harmonic profile is proposed aiming to mitigate the torque ripple in nonsinusoidal PMSMs. The proposed current control scheme is compared with conventional FOC strategy via experimental setup, demonstrating its effectiveness in torque ripple mitigation of the proposed approach.