基于混合终端滑模观测器的永磁同步电机位置和速度估计方法

Position and Speed Estimation for Permanent Magnet Synchronous Motor Based on Hybrid Terminal Sliding Mode Observer

传统滑模观测器受固有抖振特性影响,且有低通滤波器带来的反电动势观测幅值削弱和观测相位偏移,从而导致永磁同步电机(PMSM)控制精度降低。为解决该问题,提出了一种基于二阶混合终端滑模观测器的PMSM位置和速度估计方法。基于线性滑模与混合终端滑模的二阶滑模切换面,设计合理的滑模控制律,有效抑制传统滑模方法的固有抖振特性,并且能够避免使用低通滤波器所带来的反电动势观测幅值削弱和相位偏移问题,有效提高转子位置和转速的估计精度。在此基础上,进一步分析了该滑模观测器对于电机定子电阻和电感参数摄动的鲁棒性。试验结果证明了所提混合终端滑模观测器的有效性、实用性和优越性。

The control accuracy of traditional sliding mode observer (SMO) based permanent magnet synchronous motor (PMSM) was low,which was caused by the inherent buffeting characteristics,the weakening of observed back electromotive force (EMF) amplitude and the shifting of the observed rotor phase.In order to solve this problem,an estimating method for PMSM speed and rotor position based on the second-order hybrid terminal SMO was proposed.The method adopted a second-order sliding mode switching surface constructed by a linear sliding mode and a hybrid terminal sliding mode.A reasonable sliding mode control law was designed to effectively suppress the inherent buffeting characteristics of the traditional sliding mode.Besides,it could avoid the weakening of the observed back EMF amplitude and the shifting of the observed rotor phase,which were brought by the use of low-pass filter,so that the accuracy of estimated rotor position and speed could be improved effectively.On this basis,the robustness of the SMO was further analyzed with perturbation of motor stator resistance and inductance.Experimental results verified the effectiveness and practicability of the hybrid terminal SMO.