Three-Dimensional Thermal Analysis of a Rotor-Excited Axial Flux Switching Permanent Magnet Machine by Computational Fluid Dynamics Method

During conversation energy by electric machines, some energy will inevitably be wasted in the form of losses. The machine losses will be converted into heat and will increase the temperature of the machine components. Due to the dependence of electrical and mechanical properties of materials on temperature, investigating the heat transfer process in electric machines is imperative. This paper performs thermal analysis of a 2.3 kW, totally enclosed, rotor-excited axial flux switching permanent magnet (RE-AFSPM) machine for electric vehicle application by computational fluid dynamics method. Electromagnetic analysis based on the three-dimensional finite element method has been conducted to calculate losses accurately. Steady-state components temperature has been evaluated under nominal operating conditions, various rotational speeds, and different external convection coefficients. In addition, inserting blades for cooling performance of the RE-AFSPM are developed. Besides, temperature control along with the effect of the housing material on the component’s temperature has been investigated. Results indicate utilizing aluminum housing, the RE-AFSPM have better thermal performance rather than cast iron.