推力主动磁轴承的动特性参数辨识

Identification of the Dynamic Coefficients of Axial Active Magnetic Bearing

针对五自由度刚性非对称磁轴承 -转子系统 ,建立了系统动力学模型 ,在此基础上推导出系统动特性参数辨识公式 ,并用多频电流激励法辨识出参数 .与理论计算结果相比表明 :系统所建模型符合实际 ,辨识方法有效 ;径向轴承在 x和 y方向上的力 -刚度和力 -电流系数相同 ,与推力轴承对应系数相比稍大 ;推力轴承对转子横向振动产生的耦合效应明显影响系统的稳定性 。

The dynamics model of a rigid asymmetric active magnetic bearing-rotor system with five-degree of freedom is established and the identification equation of the dynamic coefficients is deduced accordingly, while the identification parameters are obtained by means of the multi-frequency excitation method. Through the comparison between the results based on the established model and the theoretical computed ones, it is proved that the identification model of the dynamic coefficients of the system and the corresponding method are valid and applicable. The coefficients of force-stiffness and force-electric current are the same along the x and y axles for the axial bearing system, while they are a little bit larger than the corresponding coefficients of the thrust bearing system. There exists a coupling effect between the axial magnetic bearing and the rotor with horizontal vibration, this has a great effect on the system stability, thus the coupling effect is in the design of the system.