Extremum Seeking Based Adaptive Compensation of Position Sensor Harmonics in PMSM Drives

Permanent Magnet Synchronous Machines (PMSMs) have become one of the preferred forms of electromechanical energy converters, attributing to their high efficiency, torque density and other unique advantages. However, given the need for proper rotor position measurement for commutation and field-orientation, accurate rotor position sensing is of paramount importance. In sensing motor rotor position with a sensor, harmonic errors that arise in the sensing subsystem lead to undesirable torque ripple. Thus, this paper presents an adaptive, extremum-seeking control-based approach capable of mitigating position signal harmonics in PMSMs. The proposed approach is experimentally validated under varying torque, speed, and harmonic conditions, and its harmonic compensation performance is comparatively evaluated with respect to the look-up table-based method. Further, the limitations of conventional lookup-table-based harmonic correction methods are analyzed, emphasizing reduced effectiveness beyond specific operating limits.