First Insights on the Electromagnetic Design of Axial-Flux Synchronous-Reluctance Maschine

This paper presents a new topology of synchronous reluctance machine, based on the axial-flux concept (AF-SynRM). As case study, an electric drive used in a cooling fan module for vehicles is considered, but the applications field can be much wider. At first, the existing/reference radial flux Interior Permanent Magnet Synchronous Motor (IPMSM) has been modeled by means of Finite Element Method (FEM) to check the electromagnetic behavior, (i.e. flux linkage and torque). The next step consists in the design and optimization of a concentrated winding, magnet-free, radial flux Synchronous Reluctance Machine (SynRM). Following that, the newly proposed AF-SynRM is benchmarked against the both magnet-based and magnet-free radial flux (RF) counterparts. As the reference machines are employing a fractional slot concentrated winding, the same is done for the AF-SynRM, even though superior behavior is expected when considering its distributed variant. Results obtained during the 3D FE-based optimization are reported highlighting the main challenges needed to be addressed (e.g. higher torque ripple and q-axis inductance). Being a motor topology that is rather complex regarding its manufacturability, possible directions and their problems are discussed.