In this study, the permanent-magnet synchronous motor sensorless control systems realised by sliding-mode observers in stationary αβ and estimated γδ coordinates are systematically studied and compared. First, based on the sufficient condition of sliding-mode stability, a more reasonable selection method of boundary layer width and sliding-mode gain is derived, effectively reducing the system chattering. Furthermore, in extracting estimated extended electromotive force, the advantages and disadvantages of the backforward method in the αβ -axis and the influence of filter cut-off frequency on estimation error in the γδ -axis are analysed. Finally, the estimation error, speed range, stability, and the effect of speed error of these two sensorless control systems are analysed and compared. The results indicate that these two systems have equivalent position error above a certain speed, and the γδ -axis estimation system has a larger position error in low-speed range, but still operating well. Moreover, the γδ -axis estimation algorithm has better stability and wider-speed range. Owing to the fast track of phase-locked loop, the effect of speed error on estimation accuracy of the γδ -axis system can be neglected. Simulation and experiment verified the theoretical analysis and comparison.

中文翻译：

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滑模观测器实现永磁同步电机无传感器控制的比较研究

在这项研究中，永磁同步电动机无传感器控制系统由滑模观测器在静止状态下实现 αβ 并估计 γδ系统地研究和比较坐标。首先，基于滑模稳定性的充分条件，推导了更合理的边界层宽度和滑模增益选择方法，有效地减少了系统的颤动。此外，在提取估计的扩展电动势时，后向方法在电机中的优缺点αβ 轴和滤波器截止频率对滤波器估计误差的影响 γδ -轴被分析。最后，分析和比较了这两种无传感器控制系统的估计误差，速度范围，稳定性以及速度误差的影响。结果表明，这两个系统在一定速度以上具有相等的位置误差，并且γδ 轴估计系统在低速范围内具有较大的位置误差，但仍然运行良好。而且，γδ 轴估计算法具有更好的稳定性和较宽的速度范围。由于锁相环的快速跟踪，速度误差对信号估计精度的影响γδ 轴系统可以忽略。仿真和实验验证了理论分析和比较。