Experimental Verification of a Rotor Unbalance Response Based Approach to the Identification of Magnetic Bearing Support Parameters

The support parameters, the stiffness and damping coefficients, of active magnetic bearings (AMBs) have direct influence on the dynamic response and stability of a rotor bearing system. The unbalance response method is a simple but effective way to identify the AMB support parameters. In this paper, we present experimental verification of this identification method. We first briefly introduce the unbalance response method and the error response surface approach to rectifying the identification error induced by the rotor flexibility. The final AMB stiffness and damping coefficients are determined as the sum of the nominal values identified by the unbalance response method and the identification errors derived from the error response surfaces. We will then present the experimental verification of this combined unbalance response and error response surface identification method on a rotor AMB test rig. In order to verify the identification method, the parameters thus identified based on the experimental data are integrated with the rotor finite element model to form the rotor-AMB model. The model unbalance response is obtained through simulation and compared with experimentally measured unbalance response. The close agreement between the model unbalance response and the experimentally measured response demonstrates that the proposed method is effective in identifying the AMB support parameters.