基于扰动观测器的永磁同步电机电流环自适应滑模控制

摘要

针对扰动对永磁同步电机转速伺服系统性能的影响,提出了基于扰动观测器的电流环自适应滑模控制方法.设计了自适应律在线估计系统的内部参数摄动以补偿模型不确定性扰动.同时,设计了滑模扰动观测器实时估计系统外部负载扰动,并将观测值前馈补偿到电流环自适应滑模控制器,在提高系统鲁棒性的同时降低滑模控制系统的抖振.实验结果显示, 采用基于扰动观测器的电流环自适应滑模控制方法,系统可快速、准确、无超调地跟踪900 r/min的速度指令,调节时间为0.08 s,稳态误差为±5 r/min.加入0.6 N·m的负载扰动,该控制方法的最大转速波动为21 r/min,比PI控制方法的转速波动减小了3.4%.仿真和实验结果表明,基于扰动观测器的电流环自适应控制方法提高了永磁同步电机转速伺服系统的鲁棒性和动态响应性能,同时可有效抑制滑模控制系统的抖振.%A current adaptive sliding mode control method based on a disturbance observer was proposed in consideration of the influence of disturbance on the performance of speed servo system in a Permanent Magnet Synchronous Motor(PMSM).An adaptive law was derived to estimate the internal parameter variations and to compensate the disturbance of the model uncertainty.Then, a Sliding Mode Disturbance Observer (SDOB)was designed to estimate the external load disturbance in real time.The estimated values were designed as a feed-forward to compensate the current adaptive sliding mode controller and to further increase the resist-disturbance capacity of the system.The experimental results demonstrate that the system based on the current adaptive sliding mode control and disturbance observer could track the speed command of 900 r/min rapidly and accurately without overshoot, the regulation time is 0.08 s, and the steady-state accuracy is ±5 r/min.When a 0.6 N·m load torque disturbance is added, the method based on current adaptive sliding mode control and disturbance observer gives a maximum speed fluctuation of 21 r/min.As compared with PI control, the speed fluctuation is reduced by 3.4%.The simulation and experimental results indicate that the proposed control method improves the dynamic response and robust performance of the speed servo system and alleviate the chattering of sliding mode control system effectively.