The speed loop is an intermediate link of the three-ring control method that within the permanent magnet synchronous motor servo system, the control method and control technology of the speed loop directly affect the dynamic response of the whole system. According to the space vector diagram and the vector control theory of permanent magnet synchronous motor, the mathematical model of the motor and the dynamic and static coordinate transformation equation are analyzed. There are some problems about speed overshoot, velocity difference integral saturation and anti-disturbance energy difference in the PI control of the speed loop. The speed loop control method based on the sliding mode variable structure is proposed. In the meantime, the sliding mode surface and switching function are designed and then the sliding mode variable structure speed closed loop controller is constructed. By means of analyzing the influence of the current loop on the back electromotive force of the motor, the current controller based on the back EMF compensation link is put forward in the design of the current loop, after that the current loop could be implified. Through the modeling and simulation analysis of the system current loop, the speed loop and the whole system, the feasibility of the speed loop control strategy can be verified.%速度环是永磁同步电机伺服系统三环控制的中间环节,其控制方法和控制技术的优劣直接影响整个系统的动态响应.根据永磁同步电机空间矢量图及矢量控制原理,分析永磁同步电机数学模型和动静态坐标变换方程,由于速度环的比例、积分(Proportion Integral,PI)控制存在速度超调、速度差积分饱和及抗扰动性能差等问题,提出基于滑模变结构的速度环控制方法,设计滑模面及切换函数,构建滑模变结构速度闭环控制器.分析电流环对电机反电势的影响,提出在电流环的设计过程中加入反电势补偿环节的电流控制器,并对电流环进行简化处理.利用仿真软件对系统电流环、速度环及系统进行建模,通过仿真研究,验证系统速度控制策略的可行性.
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