Analytical Approach for a Double-Sided Axial Flux Permanent Magnet Motor Featuring an Inner Armature Concerning Finite Permeability of Core

This paper introduces an advanced two-dimensional analytical model for Axial Flux Permanent Magnet Synchronous Motors (AFPMMs) featuring an inner armature and a double-sided topology (AFPMIADSSM). The model employs the sub-domain method to accurately determine the magnetic flux density across all regions of the motor. For this purpose, the motor geometry is partitioned into ten sub-regions: first external (FE), first rotor (FR), first permanent magnet (FP), first air gap (FAG), first winding (FW), stator core (S), second winding (SW), second air gap (SAG), second permanent magnet (SP), and second external (SE). To formulate the flux density distribution, Maxwell’s equations are analytically solved within each sub-region, and continuity conditions are enforced at their interfaces. This process results in a set of closed-form expressions for the flux density, with unknown coefficients determined through the application of boundary conditions. Furthermore, the model investigates the impact of various magnetization patterns, including parallel, ideal Halbach, two-segment Halbach, and bar magnet configurations, on the flux distribution and field alignment. To assess the accuracy and effectiveness of the proposed analytical framework, the results are benchmarked against numerical simulations carried out using the Finite Element Method (FEM), demonstrating strong agreement between analytical and numerical outcomes.