Modelling of magnetic field distributions of elliptical cylinder permanent magnets with diametrical magnetization

Abstract

This research presents semi-analytical and closed-form models to calculate the magnetic field distribution of elliptical cylinder permanent magnets with uniform diametrical magnetization at any point in three dimensional (3D) space. Using the magnetic charge approach, an accurate and fast-computed model is derived. The semi-analytical model yields results in excellent agreement with those of Finite Element Analysis. Moreover, it took less than 0.65 ms to compute each component of the magnetic field of the cylinder on a modern personal computer, which demonstrates its efficiency over the well-known Finite Element Analysis method, in terms of computation time. The accuracy and efficiency of the closed-form expressions are analysed and compared with the semi-analytical model. Two and three dimensional analyses of the magnetic field distribution of diametrically magnetised cylinders with different elliptical profiles are also conducted in this study, using the derived model. The analytical model can be used to calculate the magnetic field of an annular elliptical cylinder using the principle of superposition. In cases where the major and minor semi-axes of the elliptical cylinder are equal, it becomes a circular cylinder; therefore, the derived model can be used to compute the magnetic field of a circular cylinder with diametrical magnetization, which can be shown to outperform the existing analytical model in terms of computational cost.