Coupled Thermal-Electromagnetic Parametric Modeling of Permanent Magnet Machine Based on Flat Heat Pipe Cooling

Electrical machines with high power density and torque density are crucial to electric vehicles and more electric aircraft. Applying advanced thermal designs can help reduce the temperature rise significantly, which provides possibilities for increasing electric load and magnetic load. This paper proposes a novel cooling method that flat heat pipes are inserted into the center of in-slot windings. The thermal models of flat heat pipe and electric motor are built by lumped parameter thermal network. Simulation results show that an 85°C hot-spot temperature reduction can be achieved and more than 64% of copper loss can be removed by flat heat pipes. To predict the potential for improving performance, coupled influence of the increased cooling capacity and the reduced conductor area on the electric load is analyzed. Analysis results show that the maximum allowable operating current can be 1.6 times that of the baseline machine.