Thermal modelling of a Permanent Magnet Synchronous Machine through FEM simulation with experimental validation

Thermal characterization of electrical machines is a critical task that must be performed early in the design stages. To get accurate results, just considering the magnetic and thermal features of the machine alone may not be enough. The current harmonics, usually produced by control algorithms and electrical converters, play a critical role in the losses and, therefore, in the machine's thermal and magnetic performances. In this paper, multiphysics 2D FEM simulation is used to model a PMSM (Permanent Magnet Synchronous Machine) in two different scenarios: fed with sinusoidal currents or fed by a converter and controlled using a PWM (Pulse Width Modulation). Both, thermal steady state and transient analysis will be carried out. A complete experimental validation was performed for both cases, i.e. with sinusoidal currents and with currents generated by converter with PWM. Finally, a detailed comparison between simulation results and experimental tests is presented.