Eddy Current Loss Reflected Resistance Saliency Based Sensorless Control of SPMSM Using Rotating High Frequency Voltage Injection

Rotating high frequency voltage injection is a good candidate for sensorless control of permanent magnet synchronous motor (PMSM) at zero and low speed regions. However, satisfied sensorless performance is still challenging for surface-mounted PMSM (SPMSM) with ultra low or no inductance saliency. Aiming at this issue, eddy current loss reflected resistance saliency based sensorless control for SPMSM is researched in this article. Firstly, an improved mathematics model of PMSM considering resistance saliency is established, including both inductance and eddy current loss reflected resistance effect. Secondly, by solving the dq-axis HF (high frequency) voltage equation, it shows that resistance-based saliency can be used to estimate rotor position for SPMSM, which is key important for motor with ultra low or no saturation induced inductance saliency. Thirdly, a new heterodyne strategy is proposed to construct the position error signal for the PLL based observer, then, rotor position estimation can be achieved at steady state. Finally, the experiment results verify the effectiveness of the proposed method.