A Combined 2-D Analytical and Lumped-Parameter Thermal Model for High Power Density Permanent Magnet Machines with Concentrated Windings

This paper presents a hybrid thermal model for fast and accurate temperature prediction of high power density permanent magnet machines with concentrated windings. It combines a simplified lumped-parameter thermal network (LPTN) of the whole machine with a 2-D analytical thermal model of the concentrated winding through the Dirichlet boundary conditions. The 2-D analytical winding thermal model is intended to obtain the detailed winding temperature distribution within the slot by solving the Poisson's Equation. The proposed hybrid thermal model could calculate temperatures quickly and accurately, especially for the winding with a large temperature gradient. A test rig of a water-cooled permanent magnet (PM) machines with concentrated winding intended for electrical vehicle (EV) is implemented to validate the proposed thermal model.