Investigation of electromagnetic, thermal and mechanical characteristics of a five-phase dual-rotor permanent-magnet synchronous motor

This paper investigates of a kind of five-phase dual-rotor permanent-magnet synchronous motor (DRPMSM), which contains dual rotors and a single stator. This kind of motor has the potential advantages of high power density, high reliability and high efficiency, which make it more appropriate for using in electric vehicles (EVs). In order to evaluate the most suitable power level for this kind of structure, the electromagnetic, the thermal and the mechanical characteristics are investigated in this paper. The length to diameter ratio of motors is researched to obtain the highest power density and then the optimum ratio is obtained. Based on the optimum ratio, the thermal characteristics are researched under natural condition and forced-air cooling condition with different wind speeds. In addition, the mechanical characteristics are analyzed under no-load and different loads conditions, respectively. All of the results are analyzed by two-dimension (2-D) and three-dimension (3-D) finite element method (FEM) simulation, which provide a good reference to select suitable power level for this kind of motor structure. Finally, a DRPMSM prototype is manufactured and tested. The experimental results effectively verify the FEM results.