主动电磁轴承–刚性转子系统PID控制器设计方法

A Design Method of PID Controller for Active Magnetic Bearings-rigid Rotor Systems

PID控制策略简单、物理含义明确且适用性强,在主动电磁轴承（active magnetic bearing,AMB）系统中得到广泛应用。但是如何设计和调整控制器参数是一个实际问题。该文首先基于四自由度AMB-刚性转子系统的等效平面转子模型,给出一种简单可行的PID参数整定及设计方案。然后,在PID控制下定义AMB的等效刚度和等效阻尼,并在PD控制下分析偏置电流对AMB等效刚度和等效阻尼以及转子系统临界转速的影响,通过设置“自然”刚度和“自然”阻尼并结合P与D参数对系统临界转速以及鲁棒性的影响,完成PD参数的整定及设计,并对I参数的选择做简要分析。在一个AMB转子系统上进行数值仿真和实验,结果表明按照该文提出的PID参数整定及设计原则设计的PID控制器不仅能够使转子系统实现稳定悬浮,而且还能够使转子以较小的振动通过其刚体临界转速,实现转子在0～14000r/min转速范围内的稳定运行。

Due to the PID control strategy has the advantages of simplicity, clear physical meanings and applicability, it has been widely used in active magnetic bearing （AMB） systems. But how to design and adjust the controller parameters are practical problems. Based on the equivalent plane rotor model of four degrees of freedom AMB rigid rotor systems, a simple and feasible PID parameters design scheme was proposed in this paper. The concepts of AMB＇s equivalent stiffness and equivalent damping were used in the AMB system with the PID controller, and the influences of bias currents on the AMB＇s stiffness, damping and rotor＇s system critical speed were analyzed with the PD controller. The design and adjustment principles of the PD controller parameters P and D were completed through combining with setting natural stiffness, natural damping and the influence of P and D on the critical speed and robustness of the system. The choice of the parameter I was briefly analyzed. Finally, numerical simulations and experiments in an AMB rigid rotor system were carried out, and the results show that the PID controller based on the design and adjustment principles of P, D and I parameters proposed in this paper can not only make the AMB rotor system stable, but also make the rotor pass through the rigid critical speed with a small rotor vibration and run at a high speed region of 0-14000r/min.