Under the low speed condition, a method of real-time tracking and estimation of rotor position based on PLL technology is proposed, which is used to solve the control system detection accuracy problem of permanent magnet synchronous motor (PMSM) for electric vehicles. The control principles of high frequency signal fluctuation are analyzed, and the mathematical model of three phases PMSM under rotor estimated synchronous rotating reference frame is established. The basic principles of phase locked loop (PLL) are analyzed. Based on phase locked loop, a rotor position estimation method is designed and analyzed. Finally, simulation model of sensorless control system is set up, and the simulation experiment is carried out. The simulation experiment results show that the sensorless control based on PLL can obtain the accurate rotor positions and the excellent control ability. Therefore, the rotor positions estimation method based on PLL is an ideal method for the sensorless control of electric vehicle drive motor, which can provide theoretical and technical support for improving the control precision of PMSM and quality of electric vehicles.

针对电动汽车永磁同步电机(PMSM)控制系统检测精度问题，提出了一种基于锁相环技术的低速条件下转子位置实时跟踪估计方法。分析了高频信号波动的控制原理，建立了转子估计同步旋转参考系下三相永磁同步电机的数学模型。分析了锁相环（PLL）的基本原理。设计并分析了一种基于锁相环的转子位置估计方法。最后，建立了无传感器控制系统的仿真模型，并进行了仿真实验。仿真实验结果表明，基于锁相环的无传感器控制可以获得准确的转子位置和优良的控制能力。因此，基于锁相环的转子位置估计方法是电动汽车驱动电机无传感器控制的理想方法，可为提高永磁同步电机控制精度和电动汽车质量提供理论和技术支持。