Transient state study of electric motor heating and phase change solid-liquid cooling

This study reports on modelling of an autosynchronous electric motor stator, operating at transient state. The developed model, of the nodal type, includes around 20 nodes. The simulations showed that hot spots are localized on the winding heads and led to the choice of a solid-liquid phase change cooling system. The comparison between simulation and experiment permitted the identification of unknown parameters. The model gives a good accuracy during steady-state and in the rising temperature phase. The modelling of the phase change cooling is realized by the addition of two nodes. The sensitivity analysis to PCM properties shows that the hot spot temperature decreases with increasing conductivities, inertia and latent heat of melting of the PCM and with decreasing melting temperature. Gallium (metal melting at 30 degrees C) is the best PCM for the cooling of hot spots and P116 paraffin is the best non-metallic PCM. Copyright (C) 1996 Elsevier Science Ltd.