无轴承异步电机无径向位置传感器控制

Radial displacement-sensorless control for bearingless induction motor

针对无轴承异步电机(BIM)运行中转子位置辨识问题,提出一种基于改进反电动势法的无位置传感器控制方法.该方法在反电动势法(BEMF)的基础上,通过加入低通滤波器减小径向悬浮力绕组磁链的观测误差,同时对低通滤波器引起的相位和幅值偏差进行补偿,获得改进后的径向悬浮力绕组磁链观测模型,根据磁链-位移方程最终获取转子径向偏移,实现转子径向位移自检测.应用这种位置检测方法,建立了无轴承异步电机无位置传感器矢量控制系统,并进行仿真研究.仿真结果表明:该控制系统不仅能有效检测出转子径向位置,且具有优良的转速和转矩特性.进一步的实验结果同样表明:该方法能具有良好的位置在线自检测能力,实现了无轴承异步电机无位置传感器方式下的稳定悬浮运行.

Aimed at rotor position identification of bearingless induction motor （BIM）, a displacement-sensorless control scheme based on modified back electromotive force was proposed for the BIM. Firstly, to eliminate the flux observation error, on the basis of the back electromotive force （BEMF） method, the low pass filter was added to the flux observation model of radial suspension force winding. At the same time, the amplitude and phase deviation caused by the addition of low pass filter were compensated. Secondly, the modified flux observation model of radial suspension force winding was obtained and the rotor radial deviation was obtained according to the relationship equation between flux and displacement. Thus, the radial displacement self-detecting was achieved. Finally, a displacement-sensorless vector control system of the BIM was established using the presented position detection method. The simulation results show that the control system not only can accurately detect the rotor radial position, but also has good speed and torque characteristics. The further experimental results also show that the method had a good ability of radial displacement self-detecting. The BIM can realize stable suspension operation with displacement-sensorless.