Enhancing thermal modelling of electric machines: steady-state verification of a novel methodology

Abstract

The increasing power density of electric machines for electric vehicles necessitates accurate thermal analysis in design through simulations with computation times not exceeding one minute. Existing thermal models are either accurate and complex while requiring large computation times or they are fast but lack accuracy. To address these challenges, a novel hybrid modelling methodology is proposed, combining 3D lumped parameter thermal networks with thermal resistances extracted from 2D finite element models (FEM) to reduce computation demands while preserving accuracy. Verification of the modelling methodology against 3D FEM in OpenFOAM shows key component temperature deviations of less than 0.67 °C comparable to the 3D FEM uncertainty of 0.39 °C. The computation time is 18.3 s compared to 44 h for 3D FEM. This highlights the time-efficiency of the proposed methodology while maintaining accuracy for key component temperatures.