Temperature Prediction Method for Windings by Homogeneous Material

This paper describes the equivalent thermal conductivity for the hexagonally arranged windings and the correction method for the maximum temperature of the coil from that of the homogeneous unit. A stator with the homogenized slot is modeled with a lumped parameter thermal network (LPTN), and an analytical solution for the maximum coil temperature is derived. Because the LPTN expresses the average coil temperature, the thermal dependency of the electrical loss can be internalized into the thermal model without the coupled electromagnetic-thermal simulations. The simulational results showed that the developed model is much less computationally expensive than the all-coils-modeled FEM and produces more accurate results than the conventional method. The developed model is suitable for temperature estimation in real-time applications that simulate coil temperatures at low computational cost.