A Quasi-Three-Dimensional Magnetic Equivalent Circuit Model of Yokeless and Segmented Armature Axial Flux Motors Considering Radial Segmentation Magnetic Coupling

In this study, a quasi-three-dimensional (3D)magnetic equivalent circuit (MEC) model of yokeless and segmented armature (YASA) axial flux permanent magnet motors is proposed to realize initial fast calculation of electromagnetic performances. In the model, 3D curvature and fringing effect, flux leakage, local saturation, and the nonlinearity of ferromagnetic materials are taken into account. Besides, a radial MEC is added to consider the radial magnetic field caused by magnetic coupling between different radial sections for more accurate calculation of magnetic density. The MEC model proposed in this paper can be used to quickly predict the performances of YASA motors, including no-load magnetic density distribution and values, no-load flux linkage, back electromotive force (EMF) and torque. To verify the reliability of the model, an aero-propulsion YASA motor is taken as example. The results calculated by MEC model are in good agreement with those obtained from 3D finite element method (FEM), and the calculation time is greatly reduced from hours of 3DFEM to seconds.