An Enhanced PLL Based Sensorless Control Strategy for IPMSM with Cross Coupling Factor Estimation in Low Speed Range

This paper proposed an enhanced phase-locked loop (PLL) based sensorless control strategy for interior permanent magnet synchronous motor (IPMSM) with cross coupling factor estimation in low speed range. Ignoring the cross coupling factor would deteriorate the control performance and limit the accuracy of position estimation. In the proposed method, high frequency signal injection technique is utilized to estimate rotor position. At the same time, cross coupling factor is being estimated and will be fed back to the position observer to improve the estimation accuracy. In addition, the improved enhanced PLL proposed in this paper can eliminate the double frequency ripples caused by conventional PLL. This enhanced PLL has fast dynamic response and high robustness to the uncertainty of motor parameters, which can improve the stability of the system. The simulation results show that the proposed method has high accuracy for position and speed estimation after considering cross coupling factor and utilizing the enhanced PLL.