Analytical Model of Eddy Current Loss in Windings of Permanent-Magnet Machines Accounting for Load

This paper presents an analytical model for predicting open-circuit, armature reaction and on-load resistance limited eddy current losses in the conductors of surface-mounted permanent-magnet machines, based on the subdomain field model accounting for tooth-tips. The analytical model can be applied to machines having single-layer, two-radial-layer, or two-circumferential-layer windings. The interaction between spatial harmonics is accurately accounted for in the calculation of the AC copper loss. The investigation shows that neglecting the interaction in the analytical model has negligible influence on the prediction of total AC copper loss but results in significant error in the predicted loss distribution among conductors. The influence of tooth-tip dimension, conductor segmentation, and current on the AC copper loss is also investigated by the analytical model. The finite element analysis has verified the validity of the developed analytical model.