Improved Analytical Model for Axial Flux Permanent-Magnet Machine by Current Sheet Method

This paper presents a novel sub-domain (SD) model is presented, based on current sheet method, to reduce the order of solving matrix and computational time significantly. The permanent magnets (PMs) of axial flux permanent magnet (AFPM) machines are modeled by pairs of coils on each side of PMs in Cartesian coordinates. With the proposed method, PMs and the air-gap in the subdomain model are combined into a single region, resulting in a reduced-order solving matrix. The proposed analytical model is thoroughly described, presenting its theoretical derivation. To validate the efficacy of the model, an AFPM machine is employed and comparison is made for magnetic flux densities and the magnetic performance. Remarkably, the FEM findings align closely with the outcomes derived from the proposed method. By leveraging this theory, engineers can accurately model a diverse range of PM shapes using a low-order matrix, ensuring high accuracy.