An Accuracy Study of Finite Element Analysis-based Efficiency Map for Traction Interior Permanent Magnet Machines

While accuracy requirement for simulation-based efficiency map becomes high for traction motors which have high efficiency over wide drive range and where even a small improvement in efficiency is critical, their accuracy level has not been well studied. To evaluate the accuracy of Finite Element Analysis (FEA) based efficiency map, maps were generated with different loss calculation methods for an IPM machine. The simulation results were compared with a measurement-based efficiency map. The comparison indicated that FEA can reproduce an efficiency map with less than 1% error when losses were calculated taking into account high fidelity factors such as minor hysteresis loops, AC loss, manufacturing degradations, and stray losses. Furthermore, the sensitivities of those factors on the error were evaluated.