Active Magnetic Bearing Rotor Model Updating Using Resonance and MAC Error

Abstract

Modern control techniques can improve the performance and robustness of a rotor active magnetic bearing (AMB) system. Since those control methods usually rely on system models, it is important to obtain a precise rotor AMB analytical model. However, the interference fits and shrink effects of rotor AMB cause inaccuracy to the final system model. In this paper, an experiment based model updating method is proposed to improve the accuracy of the finite element (FE) model used in a rotor AMB system. Modelling error is minimized by applying a numerical optimization Nelder-Mead simplex algorithm to properly adjust FE model parameters. Both the error resonance frequencies and modal assurance criterion (MAC) values are minimized simultaneously to account for the rotor natural frequencies as well as for the mode shapes. Verification of the updated rotor model is performed by comparing the experimental and analytical frequency response. The close agreements demonstrate the effectiveness of the proposed model updating methodology.

Lateral Superharmonic Resonance of the Rotor in 12/8 Poles Switched Reluctance Motor

“…Under fairly wide assumptions, lateral behavior of a beam can be considered uncoupled from its axial and torsional behavior. When flexural behavior can be uncoupled from axial and torsional ones, (6) holds for flexural behavior [23]. After Z displacement and rotation angle around Z axis are constrained, freedom degrees of every node are reduced to 4, i.e., x displacement and rotation angle around x axis, y displacement and rotation angle around y axis, denoted by , , , and .…”

Active Magnetic Bearings Stiffness and Damping Identification from Frequency Characteristics of Control System

“…Secondly, the AMB rotor finite element model is built in Patran (a commercial software for Finite Element Analysis). Previous work [17] by us has already detailed the rotor modeling, model updating, and model verification of the updated model. By providing the stiffness and damping values to the bush cell and adding the same unbalance excitation for finite element model, the rotor unbalance response is simulated to obtain the unbalance displacement amplitude.…”

Rotordynamics modelling and analysis of high‐speed permanent magnet electrical machine rotors

“…Belmans et al [16] proposed an accurate modelling method of an induction motor rotor with an aluminium squirrel cage, by considering of the rotor-cage stiffness. Wroblewski et al [17,18] presented a method to minimise the modelling error through adjustment of the modulus of elasticity of model regions to a high-speed magnetically levitated machining spindle. This model updating method mainly realises the adjustment of the contribution level of the mass and stiffness for the rotor components.…”