Parameter Identification Of Active Magnetic Bearing-Rotor System Based On Model Updating Using Complex Mode And Frf

The dynamic performance of a rotor-magnetic bearings system largely depends on the bearing's dynamic parameters. It is essential to identify the exact dynamic parameters such as the stiffness and the damping so as to accurately design the bearing system and to effectively improve the rotor system's performance and stability. In this paper, two methods have been carried out based on model updating on complex bearing system(set metal rubber annuluse as sencondary vibration damper)and a group of identified dynamic parameters of the metal rubber annulus structure and active megnatic bearing have been obtained. Specific studies are as follows:The model of the metal rubber was established using finite element (FE) method with related software technologies. The spring element was performed in model updating since its high accuracy compared to the solid element. The dynamic analysis of the metal rubber which attached in the magnetic bearing system was also included in this work.Based on the data from experimental model analysis (EMA), the radial stiffness and damping parameters of the metal rubber were identified using model updating. That the errors of modal eigenvalues have a clearly decreasing trend indicates the credibility of the identified result which can be useful in the design of metal rubber structure.This research have paid special attention on some key issues including the method of model updating based on frequency response and the selection of the frequency point of the frequency response function and the definition of the residual. The method was applied on magnetic bearing-rotor system. The results show that this method was in perfect agreement with the real frequency response function from EMA. It also indicates that this method can accurately and efficiently identify the dynamic parameters of magnetic bearing system.