Three-Dimensional Analytical Model of Axial Flux Magnetic Gear Based on Harmonic Modeling

This paper introduces a mathematical method for predicting the electromagnetic performance of an axial flux magnetic gear. The analytical approach, referred to as harmonic modeling, uses a complex Fourier series and the Cauchy product to obtain solutions to the partial differential equations governing the flux-density distribution and torque values in the machines. Unlike the conventional magnetic equivalent circuit method, which provides only average quantities, the proposed approach enables the prediction of spatial flux-density distributions. A 4/15/11 model was evaluated by comparison with three-dimensional finite element method simulations. The results of the flux density and torque demonstrate that the proposed method agreed well with the FEM. An extended analysis of harmonic selection was proposed, which improves the torque prediction with errors of about 3%.