Thermal Field Analysis of Electric Propulsion Drive Motors with Flat Heat Pipe Cooling

Almost all electrical machines do not reach the limit of electromagnetic performance due to the limited material temperatures. Exploring novel thermal management methods with high cooling capacity can greatly reduce the temperature rise, which helps to increase the electromagnetic load and thus the power density and torque density. The purpose of this paper is to investigate and analyze the influence of in-slot flat heat pipe cooling method on the temperature distribution. Temperature rise and temperature distribution of the permanent magnets are the most concerned issues. The thermal performance of the surface-mounted permanent magnet motors with flat heat pipes is investigated by lumped parameters thermal network. The case study is achieved in an existing 10-kW drive motor, which is designed for an electric ducted fan. Research results show that flat heat pipes can help reduce the magnet temperature from 124.9 °C to 95.9 °C under the rated condition. However, the introduction of flat heat pipes has little effect on the temperature difference along axial direction inside the permanent magnets.