Modeling of the efficiency MAP of surface permanent magnet machine for electrical vehicles

Surface permanent magnet machines (SPM) are widely used as traction machines in the electrical vehicles due to their high power density and high efficiency. In view of the driving cycle requirements in the traction drive, efficiency of SPM over a driving cycle is more important than the efficiency of SPM at a single operating point. This paper presents an approach to model the efficiency MAP of SPM, for optimizing the average driving cycle efficiency (ADCE) of traction drive. The efficiency MAP is modeled as a series of efficiency contours, and the efficiency contour can be deduced from the motor design parameters in this paper. The finite element analysis (FEA) method is used to validate the proposed model.