Lumped Parameter Thermal Model for IPMSM Motors Including Housing, Bearing and Endcap for Vehicle Applications

One of the constraints to motor performance is temperature limits of its components. Studying performance at the system level, requires motor thermal model to be fast running and accurate. The motor configuration under study is realized into a 26-node reduced order thermal network with parameterized resistances and capacitances which shall be simulated and verified for accuracy of temperature predictions. Conduction (radial and axial) and convection heat transfer are considered for calculations. Empirical correlations are proposed for heat transfer coefficients of various parts of machine utilizing geometrical and material parameters as input. Technical papers to date have discussed radial heat transfers for main motor components. This paper investigates the radial and axial heat transfers for all motor components including housing, endcap, end plate and bearing. This model can be integrated into system models for temperature predictions of critical components or for motor optimization purposes for different motor designs and cooling configurations.