3-D Analytical Model With the End Effect Dedicated to the Prediction of PM Eddy-Current Loss in FSPMMs

The paper deals with a 3-D analytical model by considering the end effect which is dedicated to the prediction of the permanent-magnet (PM) eddy-current loss in fractional-slot permanent-magnet machines. Following the derivation of the proposed model, it is applied to the case of a 12-slot 10-pole machine with unsegmented PMs operating at rated speed. A good agreement is found while comparing the analytical results and those computed by 3-D finite element analysis. In the next step, the proposed model is applied to the investigation of the effect of PM segmentation on the reduction of their eddy-current loss, considering: 1) the radial segmentation and 2) the axial one. The obtained results highlight the better capability exhibited by the radial segmentation over the axial one in reducing the PM eddy-current loss. Finally, the proposed analytical model is applied to the investigation of the coupled-effects of the PM segmentation and geometry on their eddy-current loss reduction.