Thermal Model of the Air-Cooled Propulsion Permanent Magnet Motor Considering Heat Transfer in Outer Rotor

Permanent magnet propulsion motors are pivotal for the development of more-electric aircraft due to their high power density. This paper focuses on the thermal analysis of an outer-rotor air-cooled hybrid axial transverse flux permanent magnet motor (HATF-PMM), a topology for which temperature evaluation is particularly complex and challenging. In this paper, the thermal resistance network model (TRNM) is utilized to calculate temperature rise characteristics of HATF-PMM in complex aviation environment, which is verified by finite-element model (FEM). Considering the calculating time and accuracy, the TRNM is used to evaluate the temperature safety of the HATF-PMM under complex working conditions and flight altitude. According to the evaluation results, the suitable application of HATF-PMM is summarized. In the end, the analysis results of TRNM and FEM are validated by the prototype experiment, which proves that the proposed TRNM of HATF-PMM has advantages of the rapidity and convenience in temperature analysis and safety evaluation.