Abstract The accurate analysis and calculation of the electromagnetic field distribution characteristics are the basis for the performance optimization of active magnetic bearing (AMB). At present, the influence of eddy current and the nonlinearity of material permeability were rarely both considered in the magnetic field analysis of AMB. Therefore, the exponential equation was used to fit the magnetization curve of the silicon steel sheet to consider the nonlinearity of magnetic permeability f the material, the dynamic relative magnetic permeability was introduced to account for the influence of the eddy current. Then a nonlinear equivalent magnetic circuit model (NEMC) of radial AMB was established with the edge effect, stator and rotor core reluctance, nonlinear magnetic permeability, eddy current influence and real-time control current. Using this model, the magnetic field distribution in the air-gap was calculated when the rotor had a static displacement of 0.1mm. The results are in good agreement with the finite element simulation (FEM) results, and the relative error in the opposite of magnetic poles is basically less than 3%. In addition, the influence of eddy current caused by rotor period vibration on magnetic flux and electromagnetic force was analyzed. After considering the eddy current, the magnetic flux and the electromagnetic force decrease, and the higher the vibration frequency, the greater the attenuation.
Ye Pinzhou,Li Hongwei,Yu Wentao等. Equivalent Magnetic Circuit Modeling of Radial Active Magnetic Bearing Considering Material Nonlinearity and Eddy Current Effects[J]. Transactions of China Electrotechnical Society, 2020, 35(9): 1858-1867.
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2020, Vol. 35 
