Thermal Modeling of PCB Windings for Slotless PM Motors

In this paper, a thermal circuit model is developed for PCB windings used in slotless PM motors, to calculate the temperature of the copper traces. The thermal circuit model for this topology is derived by considering concentric cylindrical shells in contact with each other and stacked on top of one another as it is easy to calculate thermal resistances considering radial and axial directions of heat transfer and total heat generation in such an arrangement. The mean body temperatures calculated analytically using the thermal circuit model are then verified using finite-element analysis.