3D Finite Element Analysis Method for the Characterization ofAxial Flux Permanent Magnet Synchronous Machines:Application to Hybrid Electric Vehicles

International audienceIn the context of vehicle electrification, car manufacturers are facing ever more constrainingstandards. Consequently, embedded electrical machines which are criticalcomponents of a vehicle power system have to be highly efficient and remain at anacceptable cost. In the HEV and EV markets, permanent magnet synchronous machine(PMSM) have now reached a major place thanks to their high torque/powerdensity, their high efficiency and their large constant power speed range capability(Z.Q. Zhu and D. Howe, ”Electrical Machines and Drives for Electric, Hybrid,and Fuel Cell Vehicles” in Proceeding of the IEEE, Vol. 97, No 4, 2007). Axialflux permanent magnet synchronous machines (AFPM) provide high compactnessand high torque capability, due to their particular disc-shaped geometry, and consequentlyappear as a relevant solution for HEV (A. Cavagnino, M. Lazzari, F.Profumo and A. Tenconi. ”A Comparison Between the Axial Flux and the RadialFlux Structures for PM Synchronous Motors”, in IEEE Transactions on IndustryApplications, Vol. 38, No. 6. 2002). However, 3D aspects relative to an axial fluxmachine electromagnetic problem are to be considered for an accurate analysis.Therefore, 3D-FEA is required though their computation is time consuming.For a variable-speed traction application, requirements usually comprise torque/powerversus speed profiles and voltage and current inverter rankings. FEA is then an efficientway to check these requirements and to know better the machine charactericsas well. At this point, it is not obvious to decide which simulation is necessary (e.g.magneto-static or magneto-dynamic application) and what are the interesting valuesto analyse each time. Moreover, it is important to choose a convenient configurationof the simulation and to determine an efficient simulation sequence. This problembecomes even more relevant when several machines are to be compared. In thisperspective, this paper proposes a methodology to deal with 3D-FEA of an AFPMmachine using CEDRAT-Flux3DR commercial software. According to the designrequirements, it is explained the necessity of each simulation, and the sequence inwhich it should be achieved. A particular emphasis on simulation configuration (i.e.meshing and parametric discretization) is provided. Finally, a comparison betweena surface mounted permanent magnet synchronous and an interior permanent magnetsynchronous machine, both axial flux structures, is proposed to illustrate theapproach. Problem definition and solving processes times are given to show howthis methodology can be profitable