Performance improvement of PMSM rotor position estimation by using adaptive hybrid filter based PLL

Abstract

To achieve a satisfactory sensorless control performance of permanent magnetic synchronous machine (PMSM), an effective rotor position estimation method is a critical factor. As a useful tool for phase estimation technique, there exists extensive application of phase-locked loops (PLLs) in this task. Nevertheless, since harmonics are existed in the back electromotive force (EMF), the accuracy of position estimation method based on PLL is still low. In this paper, an adaptive hybrid filter based PLL is proposed to enhance the estimation performance. The proposed adaptive hybrid filter is frequency-adaptive, which means the performance is not affected under varying-speed operating conditions. Moreover, all the harmonic disturbances can be totally eliminated. The proposed method is validated under simulation. The results confirm the effectiveness of the proposed method.

Keywords

• Phase-locked loop
• PMSM
• Position estimation