Analytical Modeling of an Eddy-current Adjustable-speed Coupling System with a Three-segment Halbach Magnet Array

This article presents a two-dimensional analytical model to predict the magnetic field distributions and torque characteristics in an axial-flux eddy-current adjustable-speed coupling system with a three-segment Halbach magnet array. The main contribution of this article is the analytical evaluation of a moving-conductor eddy-current problem based on a three-segment Halbach magnet array by considering the influence of the eddy currents on the magnetic field. Based on the layer model method, the three-dimensional eddy-current problem is linearized to a two-dimensional problem, and the field equations derived from Maxwell's equations in each layer (iron core, magnet, air gap, and conductor) are solved by using the variable separation method and Cramer's rule. The proposed analytical model is validated by the three-dimensional finite-element method in terms of both magnetic field prediction and parameter analysis. Because the analytical methods take less computational time than numerical methods, they are an effective tool for the first step of design optimization.