Initial Rotor Position Estimation by Detecting Vibration of Permanent Magnet Synchronous Machine

Abstract

The principal methods of initial rotor position estimation of permanent magnet synchronous machine (PMSM), such as high-frequency rotating signal injection methods and high-frequency pulsating signal injection methods, are implemented by calculating the voltage equations of the stator winding. However, these methods have low adaptability to the PMSMs with different saliency properties and high sensitivity to electrical parameter variations. In this article, an initial rotor position estimation method based on the dynamical equations of the PMSM is proposed to solve the abovementioned problems. First, a series of vibration signals of the PMSM is generated by applying a high-frequency voltage to the rotating virtual d-axis of the rotor. Then, the relationship between the vibration signals and the rotating virtual d-axis position is established. Next, the initial d-axis rotor position of the PMSM is estimated by analyzing the vibration response. Finally, the rotor magnetic polarity is identified on account of the saturation saliency effect. The theoretical analysis and simulation, as well as experiments, are carried out to verify the effectiveness and accuracy of the innovation method. The results demonstrate that the proposed method has the advantages of easy implementation, high adaptability, and strong robustness; also, the maximum initial rotor position estimation error of the proposed method is 1.7 electrical degrees, which is lower than other methods.