基于电涡流传感器的无轴承永磁薄片电机转子初始位置快速检测方法

A Fast Initial Rotor Position Detection Method for Bearingless Permanent Magnet Slice Motor Based on Eddy-current Sensors

针对无轴承永磁薄片电机转子初始位置检测困难、进而启动与悬浮难以同步的问题,提出了一种基于电涡流传感器快速检测电机转子初始位置的方法。利用永磁体与铁磁体之间始终趋向于磁阻最小的特性,首先通过由电涡流传感器检测到的转子偏移量确定永磁体某一磁极指向,初步假定同步坐标系d轴正方向。然后在此基础上,通入悬浮力电流观测转子是否回归中心位置,进一步精确判定永磁体N/S极分别所指方向,从而得到正确的转子初始位置信息。以TMS320F2812控制的一台4kW无轴承永磁薄片电机系统完成验证实验。结果表明,所提出方法能够准确检测出转子的初始位置,实现电机在悬浮状态下的平稳启动要求。

Aiming at the problems of rotor off-center position and the uncertain initial angle before starting bearingless permanent magnet slice motor,a fast initial rotor position detection method based on eddy-current sensors was proposed.By using the characteristic of the minimum reluctance between the permanent magnet and iron magnet,a pole pointing of the permanent magnet was determined by direction of rotor’s drift detected of the eddy current sensors firstly,and the positive direction of d axis was preliminary set.Then observing whether or not the rotor was back to the center by injecting the suspended current,the N/S polarity can be acquired accurately.The experimental results verify the feasibility and effectiveness of the proposed method by a 4kW bearingless PM slice motor used TMS320F2812 control.It shows that the detection method can accurately determine the initial position of the rotor,to achieve the smooth start of the motor in the suspended state.