Enhanced 3D finite element method analysis of a permanent magnet machine with reduced stator-core iron losses

摘要

The main requirements for a rotating electric machine for traction applications are the torque/power density and the energy efficiency. Nowadays, an impressive effort is done to improve the efficiency even with a small fraction without compromising the torque density. With increasing availability of high performance computing and the acute interest for efficiency improvement, the simple empirical approaches to estimate the iron loses may have come to their limits. A comprehensive understanding and modeling of the loss production mechanism is required to accurately predict the performance of such an electric machine. Therefore, in this paper the end-winding stray field is analyzed and the additional iron losses in the end region of the stator core are presented and assessed. For this purpose, enhanced 3-D finite element models, including the complex end-winding geometry, are computed on a parallel distributed high performance computing system. To emphasize the benefit of this enhanced 3-D finite element modeling a 100 kW case study traction permanent magnet machine with improved efficiency at high speed is proposed.