基于双线性变换的IPMSM无传感器控制

Sensorless Control of IPMSM based on Bilinear Transformation Method

内置式永磁同步电机具有效率高、易于弱磁扩速等优点,广泛应用在新能源汽车、航天和家用电器等场合。为了提高电机系统的可靠性,降低其成本,无位置传感器控制技术获得了广泛研究。本文针对内置式永磁同步电机(IPMSM)在低速下反电动势非常小因而难于观测转子转速和位置的问题,使用了一种高频注入方法。在对比分析后选择高频脉振注入法作为激励方法,在滞后dq坐标系45°的测量坐标系中处理高频电流响应,并对比了2种经后向欧拉法和双线性变换法离散化的锁相环环路滤波器的效果,同时采用零极点配置法设计锁相环的压控振荡器。仿真和实验结果表明转子位置误差可以保持在0.1rad以内,可以有效地观测低速时IPMSM的转子位置。

The interior permanent magnet synchronous motors(IPMSM) which are widely used in the new energy vehicles, aerospace and household electrical appliances have the advantages of high efficiency and flux weakening. In order to improve the reliability of the motor system and reduce the cost, sensorless control of PMSM is widely researched. In view of IPMSM operating at low speed case, the back electromotive force(BEMF) of motor is very small, as the result, the speed and position are difficult to be observed. Based on analysis of two kinds of injection methods, the high frequency pulsating voltage injection method is used to extract the rotor position. A novel rotor position observer on account of phase-locked loop(PLL) is proposed in this paper. The high frequency current response is dealed in a measurement coordinate with a 45° lagging compared with dq coordinate. The bilinear method and backward Euler method are quoted to discretize the loop filter(LF) of PLL. The zero pole assignment method is used to design the voltage-controlled oscillator(VCO) of PLL. The simulation and experimental results show that the rotor position error can be controlled within 0.1rad and can effectively observe the rotor position of IPMSM at low speed.