A Novel Quasi-3D Analytical Model for Axial Flux Motors Considering Magnetic Saturation

The magnetic field calculation for axial flux motors (AFMs) is always intricate and time-consuming. To this end, a fast quasi-three-dimensional (3D) analytical model is proposed in this paper for magnetic field prediction in AFMs. By dividing the AFM into several annular slices in the radial direction, the 3D magnetic field problem can be simplified into a two-dimensional (2D) one. Then, the harmonic modeling method (HMM) in Cartesian coordinates is adopted to solve the magnetic field in these slices cut from the AFM for the first time, and the corresponding electromagnetic parameters of the AFM can be acquired subsequently. The critical step for the field prediction of using HMM in Cartesian coordinates is to adopt a variable substitution method when solving the partial differential equations. The magnetic saturation of soft-magnetic material within AFMs is considered by adopting an iterative approach. Ultimately, the effectiveness of the proposed quasi-3D analytical model is validated by the nonlinear finite-element analysis (FEA). The proposed analytical model is computationally efficient, which makes it suitable for the preliminary design of AFMs.