Magnet Loss Computation for PMSMs Under PWM Supply via Corrected Magnetostatic FEA

This paper introduces a method to make magnetostatic simulations applicable for computing the permanent magnet loss in PM synchronous machines. Conventional magnetostatic finite-element analysis simulations fail in modelling the eddy current reaction field, leading to a significant overestimation of magnet loss. Consequently, this study provides a comprehensive post-processing manipulation of the magnetostatic field solution to appropriately consider the impact of the reaction field under sinusoidal and PWM supply. Furthermore, the paper addresses the three-dimensional effect, namely the additional loss due to the eddy currents path on the magnet's axial end-side, which is normally addressed via time-consuming 3D simulations. The proposed method is showcased on a motor having the same dimensions and ratings as the Tesla Model 3 interior PM rear-axle motor, highlighting the magnet loss boost caused by the PWM harmonics. The approach presented in the paper leverages a dedicated formulation based solely on 2D magnetostatic analysis, effectively exceeding the capabilities of conventional 2D transient commercial solvers. The obtained results are compared with the transient solution obtained with the commercial solver Ansys Maxwell.