Influence of an end-winding size on proximity losses in a high-speed PM synchronous motor

This paper deals with AC winding loss including proximity loss investigation in a high-speed permanent magnet (PM) machine for traction applications. The research is focused on the end-winding effects that have not been widely reported in the literature. The calculated results confirm that the end-winding copper loss can significantly affect the eddy-current loss within copper and it must be taken into account to provide reasonable prediction of total losses. A three-dimensional (3D) finite element analysis (FEA) is employed to evaluate and identify the end-winding contribution into the overall winding power loss generated. To explain how much the power loss may change due to dimensions and size of end-winding, the parameterized 3D FE models are investigated. In this study, the results clearly demonstrate that the size of end-winding has influence on the winding resistance and, consequently, the power loss in the AC operation. The theoretical prediction of the losses within the armature of the high-speed permanent magnet synchronous machine (PMSM) is validated experimentally on a segmented stator.