基于转速的磁悬浮轴承转子系统变参数控制

Variable parameter control of active magnetic bearing rotor system based on rotation speed

建立了磁悬浮轴承柔性转子系统数学模型。分析了磁悬浮轴承的支承特性、系统在不同控制参数下的稳态不平衡响应和在旋转状态下控制参数变化对系统稳定性的影响,提出了基于转速的变参数控制策略。构建了五自由度磁悬浮轴承转子系统试验台,将转速信号引入数字控制器,在不同转速区段采用不同PID参数控制磁悬浮轴承,进行了高速旋转试验。理论分析和试验结果表明,在不同转速区段采用不同控制参数,可以同时满足系统在低频段和高频段动态性能的要求,有效减小转子的不平衡振动,有利于系统平稳越过临界转速。

A mathematical model of Active Magnetic Bearing （AMB）-flexible rotor system is built in the paper. Supporting characteristic of AMB, unbalanced stationary responses of the system under control with different parameters and the influences of control parameter variation on system stability in rotating state were analyzed, and variable parameter control strategy based on rotation speed was put forward. The experimental setup for 5 DOF active magnetic bearing-rotor systems was established. The signal of the rotation speed was introduced into the digital controller, different control parameters were adopted in different rotation speed section, and dynamic characteristics of the system with variable parameter control strategy were investigated. Theoretical analysis and experimental results show that the variable parameter control strategy can meet re- quirements of low-frequency and high-frequency dynamic characteristics of the system synchronously, thus reducing unbalance vibration of the rotor effectively, and making for stably passing the critical speed of the rotor system.