Comparison of axial flux machine performance with different rotor and stator configurations

Abstract

Axial flux machines (AFMs) are used in applications that require high power and torque densities in a pancake-type form factor. There are various types of AFMs based on the configuration of the rotor/stator and magnet orientation. In this paper, a comprehensive analysis and comparison of AFMs with different rotor and stator configurations are presented. Considered topologies are: slotted AFMs with single stator single rotor (SSSR), double stator single rotor (DSSR) and single stator double rotors (SSDR). The effect of magnet orientations such as interior permanent magnet or surface permanent magnets is also considered. The analytical sizing equations are used as a first step then optimizations are performed through the 3D finite element analysis (FEA) to attain maximum torque density while staying within the mechanical and electrical constraints. The performances of the AFM types are compared with respect to torque density, power factor and efficiency.