基于复合PI控制器的永磁伺服电机电流控制

Current control of permanent magnet servo motor based on compound PI controller

在永磁电机伺服系统中,电流环PI控制器通常基于零极点对消的方式设计得到,这会限制系统动态性能的提升。针对这一问题,首先通过传递函数分析说明传统电流环PI控制器存在的问题,然后基于状态方程设计电流环复合PI控制器。通过传递函数进行对比,从理论上说明电流复合PI控制器比传统电流PI控制器具有更好的抗扰性能,并给出相应的约束条件。最后,通过实验对比电流阶跃响应和跟踪正弦给定响应。实验结果表明,采用复合PI控制器的电流控制系统对正弦给定的跟踪误差更小,电流阶跃响应也更快,即电流复合PI控制系统具有更好的跟踪性能和抗扰性能,证明了所提方法的有效性。

As the traditional current PI controller in the permanent magnetic servo system is designed based on the zero-pole cancellation method, improvement of the system dynamics is restricted. To solve the problem, the transfer function was used to analyze the problem of the traditional PI controller for cur-rent loop first, followed by the design of the compound PI controller based on the state equation. The comparison between the transfer functions of the two system was used to clarify that the compound PI con-troller is better in disturbance rejection ability than the traditional one, and the corresponding constraint condition was given. Finally, experiments of step response and tracking sinusoidal reference was illustra-ted to verify the effectiveness of the proposed method. The experiment results show that the system using the compound PI controller has the merits of smaller tracking error and faster step response, which means that the tracking performance and disturbance rejection property of the system is better when using the compound PI controller, and effectiveness of the proposed method is verified.