基于MRAS的永磁同步电机无传感器滑模控制

Sensorless sliding mode control of permanent magnet synchronous motor based on MRAS

为了改善转速误差的估计信息及转子位置估计误差信息,提高了误差的准确度,在三相永磁同步电机的矢量控制算法中,基于MRAS观测器采用滑模变结构速度控制器代替PI速度控制器,将PI控制与模型参考自适应系统结合起来。并且针对滑模变结构的不连续性所引起的转速抖动,利用正弦饱和函数的光滑特性对滑模速度控制器进行优化。首先在三相永磁同步电机的矢量控制系统的基础上,根据算法公式建立了参考模型自适应观测器,再设计滑模面建立控制模型,最后通过MATLAB仿真软件进行实验。理论与仿真分析结果表明,改进后的系统将PI控制器的超调量消除,并且转速到达稳态的过程所花费的时间大大减小,转速误差估计值与转子位置估计误差的精度更高,系统整体鲁棒性得到加强,检测精度增高。

In order to improve the estimation information of rotational speed error and rotor position error,and improve the accuracy of the error,in the vector control algorithm of three-phase permanent magnet synchronous motor,based on MRAS observer,sliding mode variable structure speed controller is used instead of PI speed controller,and PI control is combined with model reference adaptive system. In order to solve the speed jitter caused by the discontinuity of sliding mode variable structure,the sliding mode speed controller is optimized by using the smooth characteristic of sine saturation function. Firstly,based on the vector control system of the three-phase permanent magnet synchronous motor,the reference model adaptive observer is established according to the algorithm formula,then the sliding mode surface is designed to establish the control model,and finally the experiment is carried out by MATLAB simulation software. Theoretical and simulation results show that the improved system eliminates the overshoot of PI controller,and the time taken for the speed to reach steady state is greatly reduced. The accuracy of the speed error estimation and the rotor position estimation error is higher,the overall robustness of the system is enhanced,and the detection accuracy is increased.