带电阻在线辨识的改进型永磁同步电机滑模观测方法

Study on improved sliding-mode control with resistance estimation of PMSM

针对永磁同步电机定子电阻的不确定性及传统滑模观测存在的固有抖振问题,提出一种带电阻在线辨识的无速度传感器改进型滑模观测方法。该方法在传统滑模观测器的基础上,采用可变边界层厚度的Sigmoid函数来取代Sign函数,并结合转速大小动态调整观测器增益;同时引入电阻在线辨识环节,运用李雅普诺夫函数设计了电阻参数在线辨识算法,并用于实时修正滑模观测器参数。仿真和实验结果表明,与传统的滑模观测器相比,该算法能够有效地抑制滑模观测器的抖振现象,转速估计对电阻变化的鲁棒性得到增强,提高了永磁同步电机驱动系统在整个调速范围内的观测精度。

The stator resistance uncertainty and the inherent chattering of the traditional sliding mode ob- server exist in permanent magnet synchronous motor （PMSM） sensorless variable frequency speed control system. An improved sliding mode observer with online stator resistance identification was designed to op- timize the performance of PMSM drive system. Based on the principle of the conventional sliding mode observer, a sensorless control strategy that substitutes a Sigmoid function for the Sign function with a variable boundary layer was proposed,which can dynamically adjust the observer gain according to the speed. In order to eliminate the effect of the uncertainty of the stator resistance on speed estimation and improve the accuracy of sliding mode observer, the algorithm identified stator resistance online which can help update the parameters of sliding mode observer by using the Lyapunov function. The results of simulations and experiments show that, compared with the traditional sliding mode, the proposed algorithm can suppress the chattering problem, enhance the robustness of speed estimation in the effect of the uncertainty of the stator resistance and thus estimate PMSM drive system with high accuracy.