2D analytical model for estimation of eddy current loss in the magnets of IPM machines considering the reaction field of the induced eddy currents

In this paper a closed-form 2D analytical model developed for the estimation of eddy current loss in interior permanent magnet machines is presented. To check the generality of the developed model, two different types of commonly employed interior permanent magnet machines are considered. 2D finite-element analysis was used to benchmark the results from the analytical model. The proposed model can be directly used to evaluate the eddy current magnet loss for magnet segmentation in the circumferential direction. The influence of air-gap length, frequency of carrier harmonic, reaction field and non-linearity of iron due to saturation on the magnet loss have been studied in detail and the results are presented. The effect of axial segmentation has been considered by incorporating an end-effect factor in the analytical model. The results from analytical and 2D finite-element analyses are found to be in concurrence.