考虑转速及温度影响的磁轴承分散PID控制器参数优化设计

Optimal design of decentralized PID controller parameters for AMB considering influence of revolution speed and temperature

传统磁轴承控制器设计过程多使用定参数磁轴承-转子系统动力学模型,难以保证良好的控制器性能。为此,考虑磁悬浮旋转机械运行过程中转速及温度对系统模型参数的影响,建立了变参数系统模型,进而对磁轴承分散PID控制器参数进行了优化设计。首先,转速影响轴承气隙的原理是材料的泊松效应,温度则是通过定转子热膨胀位移差影响轴承气隙,由此建立轴承支承力变参数模型;其次,考虑温度对转子材料弹性模量的影响,建立了考虑转速及温度影响的变参数系统模型;再次,以控制系统广义幅值裕度及灵敏度的加权值为优化目标,使用遗传优化算法对分散PID控制器参数进行了优化设计;最后,在测试平台上验证了所提磁轴承控制器参数优化设计方法的有效性。

The traditional design process of magnetic bearing controller often uses the dynamic model of magnetic bearing-rotor system with fixed parameters,which is difficult to ensure controller with good performance.The influence of revolution speed and temperature on the system model parameters during the operation of maglev rotating machinery were considered,and a variable parameters system model was established,and the parameters of decentralized PID controller were optimized.Firstly,the influence principle of revolution speed on bearing air gap was because of the Poisson effect of the material,and the temperature changed the bearing air gap by the thermal expansion displacement difference of the stator and rotor,thus the variable parameters model of bearing force was established.Secondly,considering the influence of temperature on the elastic modulus of the rotor material,a variable parameters system dynamic model was established.Thirdly,the genetic optimization algorithm was used to optimize the parameters of the decentralized PID controller,with the weighted value of the amplitude margin and sensitivity of the control system as the optimization objective.Finally,the effectiveness of the proposed AMB controller parameters optimal design method was verified on the test platform.