Design and analysis of PMSM motors-thermal behaviours using CFD simulations for EV-two wheeler applications

Thermal management is an essential aspect that affects the reliability and performance of the traction motors used in electric vehicles. In this paper, the design and thermal analysis of the proposed 5 kW rated Permanent Magnet Synchronous Motor (PMSM) that can be used in electric two-wheelers is carried out under passive cooling conditions. The design parameters such as rotor-stator configuration, slot-pole combination, and winding arrangement have been chosen to maximize the torque density and efficiency of the proposed motor. A three-dimensional thermal analysis has been carried out using ANSYS CFD to analyse the heat generation and dissipation characteristics of the proposed motor during steady-state operation. The heat generation sources such as copper losses, core losses, and eddy currents have been identified as the main heat sources in the proposed motor. The maximum temperature rise is observed in the stator winding, which is found to be 136°C, 24% lower than the maximum allowable limit of 180°C. The permanent magnets and the PCB attain a maximum temperature rise of 129°C and 116°C, which is 14% and 11% lower than the maximum allowable limit of 150°C and 130°C, respectively. From the thermal contours, it is evident that the heat generation is maximum in the stator windings and teeth, while the housing plays a role in the heat dissipation process. This proves that the proposed design of the PMSM is operating within the safe limits and can be used for continuous operation in electric two-wheelers.