Thermal modelling of Multi-Phase Permanent Magnet Synchronous Motor for traction of low voltage Electric Vehicle.

In this thesis it has been analysed a permanent magnet synchronous motor (PMSM) of a battery electric vehicle (BEV) with a V-shaped magnets in the rotor, six-phase at 52 V, 12 conductors per slot. Two modes have been distinguished: dual mode, which uses six-phase active inverters, and the frugal mode, which has only one inverter with three-phase active. The machine is cooled with an housing water jacket in spiral configuration, assuming a constant volume flow rate and given inlet coolant temperature. Different drive cycles have been analysed for the two configurations: acceleration cycle 0-100 km/h; climbing cycle with 20 % slope; WLTP Class 3 cycle. It has to be noticed that the WLTP cycle for the frugal mode has been simulated only for the first thousand seconds, which is the urban part of the cycle. Two models have been used to estimate the thermal behaviour of the motor: a lumped parameter thermal network (LPTN) developed in Motor-CAD software and a reduced-order thermal model (ROTM) in Simulink.