High-Precision Commutation Error Compensation Strategy for Magnetically Levitated PMSM Using Eddy Current Sensors

Stable suspension and precise rotor control remain critical challenges in magnetically levitated permanent magnet synchronous motors (PMSMs). While eddy current sensors are widely employed for displacement measurement in magnetic suspension systems, they are generally not considered suitable for rotor position angle detection due to their nonlinear characteristics and sensitivity to external disturbances. This article proposes a novel approach that leverages eddy current displacement sensors to estimate the rotor position angle in a magnetically levitated PMSM. First, the operating principles and inherent limitations of eddy current sensors are analyzed. Then, the impact of installation misalignment and temperature drift on position detection accuracy is investigated. To mitigate these effects, a compensation algorithm is developed to correct rotor pole angle errors in real time. Finally, the proposed method is validated on a dedicated magnetically levitated PMSM experimental platform. The results confirm its effectiveness and demonstrate its potential to reduce system complexity and improve detection reliability.