Calculation of eddy current loss for magnetic thrust bearings

Abstract

A magnetic circuit model of eddy current loss for a magnetic thrust bearing (MTB) is presented based on the effective reluctance and the magnetic circuit theorem. Considering the skin effect of eddy current, the effective reluctance is introduced into the flux path, and the magnetic flux, coil impedance and eddy current loss are analysed. In addition, a harmonic analysis on the finite element method model of the MTB and the magnetic circuit model is conducted and the results are compared in consideration of such affecting factors as material non-linearity, leakage, and fringing flux. It shows that the magnetic flux and the coil impedance have the same frequency domain properties in the above two models. The eddy current losses derived from these two models agree well with the experimental results.

Keywords

magnetic circuit model magnetic thrust bearing effective reluctance skin effect eddy current loss finite element method

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