Torque Ripple Minimization of PMSM Using Resonant Controller in Robot Applications

Torque ripples in Permanent Magnet Synchronous Motors (PMSMs) are a significant challenge in high-precision applications, as it limits servo control accuracy and speed stability. A novel scheme is proposed to minimize torque ripples by a resonant controller based on speed harmonic minimization in this paper. This scheme leverages the relationship between speed harmonics and injected voltage harmonics, where the voltage harmonics are directly generated by the speed resonant controller responding to the detected speed harmonics. Compared to state-of-the-art methods for reducing torque ripple, the proposed scheme is simpler to implement in robotic systems, as it abandoned current harmonic compensation link and does not depend on specific motor parameters or motor control parameters. It has been simulated and experimentally validated under two test benches. The results demonstrate that the proposed scheme enhances servo system control accuracy.