主动电磁轴承-柔性转子系统的不同位效应

Non-collocated effect on active magnetic bearing-flexible rotor systems

在电磁轴承支承的柔性转子系统中,由于结构的限制,位移传感器无法安装在电磁轴承的中心位置,因而产生了传感器中心位置与电磁轴承中心位置的不同位问题。电磁轴承和位移传感器的不同位不仅会影响转子系统的振动控制性能,还会导致控制系统失稳。应用有限元法建立了电磁轴承-柔性转子系统的动力学模型;从转子系统动力学特性、开环传递函数的零极点、频率响应曲线以及根轨迹等四个角度分析了不同位对电磁轴承-柔性转子系统动力学特性的影响;用多输入多输出的状态方程确定了不稳定模态特征值的具体位置,提出了减小控制器增益和插入式自适应陷波器等抑制不稳定弯曲模态的方法;在电磁轴承-柔性转子试验台上进行了试验。仿真和试验结果表明:不同位效应会通过影响模态信号的衰减而影响转子系统的稳定性,所提出的方法可在一定程度上抑制不同位导致的弯曲模态的不稳定。

Due to the structural limitations in the flexible rotor system supported by Active Magnetic Bearings,displacement sen-sor cannot be installed inside the bearings,which results in the non-collocation effect.The non-collocation of rotor system will not only decrease the vibration performance of rotor system,but also cause system instability.In this paper,the dynamic model of the active magnetic bearing-flexible rotor system is established by the finite element method.Through the dynamics characteristic,open loop transfer function,frequency response,and root locus method,the features of the non-collocation system are studied.The specific positions of the unstable mode eigenvalues are analyzed by the multi-input and multi-output state equation.Solutions including reducing the controller gain and adaptive plug-in notch filter are proposed to suppress the unstable modes because of non-collocation effect.Experiments are designed in a flexible rotor system test rig.The experiments’results show that the rotor system’s stability is influenced significantly by non-collocation effect.The method proposed in the passage can suppress the instability of bending modes caused by different potential effects to a certain extent.