基于Smith预估器的永磁电机高动态响应电流环控制策略

High-Dynamic-Response Current Loop Control Strategy of Permanent Magnet Motor Based on Smith Predictor

高性能永磁电机伺服系统需要快速的电流响应,数字控制系统中的延时环节会制约电流环动态性能。为此,该文推导了矢量控制系统中主要延时环节的数学模型并分析其不利影响;在此基础上,引入Smith预估算法,针对永磁电机电流环的高动态响应要求,提出一种Smith预估电流控制器,给出该电流控制器的设计过程及实现方法,并讨论了电机参数敏感性。仿真与实验结果表明,所提控制策略正确有效,而且能对控制系统的延时环节进行较好补偿,可有效改善电流环动态性能,进而有助于提高伺服系统整体性能。

High performance permanent magnet motor servo system needs fast current response.The delay link in digital control system will restrict the dynamic performance of current loop.For this reason,this paper deduces the mathematical model of the delay link in vector control system and analyses its adverse effects.Accordingly,Smith predictive method is introduced,and a Smith predictive current controller is proposed for the high dynamic response requirements of the current loop.The design process and implementation method of the current controller are given,and the sensitivity of motor parameters is discussed.The simulation and experimental results show that the proposed control strategy is correct and effective.It can compensate the delay link of the control system,improve the dynamic performance of the current loop effectively,and then improve the overall performance of the servo system.