The thermal design of a 6-phase fractional-slot interior permanent magnet (IPM) machine having a novel 18-slot, 8-pole topology is presented using 2D electromagnetic finite-element analysis (FEA) and a lumped parameter thermal model. This presentation describes the approach to calibrate loss models and to validate the thermal model using the experimental tests. It discusses the thermal challenges imposed by the operating conditions and the driving cycles on the motor components.
