Analysis and Suppression of Rotor Eccentricity Effects on Fundamental Model Based Sensorless Control of Permanent Magnet Synchronous Machine
Ximeng Wu, Z. Q. Zhu, Wu Zhong, T. Y. Liu, Yanxin Li
Abstract
In the past, various fundamental model based sensorless control methods have been proposed. However, most of them are developed under a healthy condition. Hence, in this article, fundamental model based sensorless control of permanent magnet synchronous machines (PMSM) under rotor eccentricity (RE) is investigated which is a common issue in many drive systems. It is known that under RE, three-phase back-EMFs, flux-linkages, inductances, and torque will be influenced. Mathematical derivation reveals that these effects will cause undesired harmonics in the position estimation. Since the frequencies of these low-order harmonics are much smaller than the bandwidth of position observer such as phase-locked loop, it is difficult to effectively eliminate them. Hence, the conventional back-EMF method is modified by adding an adaptive notch filter to suppress these undesired harmonics. Furthermore, the RE effects on PMSM characteristics are examined by measurements. The modified position estimator is implemented on a dSPACE platform and is verified by experiment results.