A new nonlinear anisotropic model for soft magnetic materials

An accurate and efficient nonlinear anisotropic model for soft magnetic materials is developed. In this model, the cross effects of the magnetic field in the different principle directions are decoupled by introducing an equivalent magnetic field magnitude in each principle direction. This equivalence is based on an anisotropic characterization of the energy density. Only B-H curves in the principal directions of the materials-two curves in two-dimensions or three curves in three-dimensions-need to be measured. The anisotropic behavior of laminations with either isotropic or anisotropic steel is also considered. The model is validated by numerical experiments and is applied to three-dimensional finite element analysis of a synchronous reluctance motor with an axially laminated anisotropic rotor

I. Introduction

While anisotropic behavior is often encountered in electromagnetic devices, current models available to characterize this behavior are inadequate. In particular, the accuracy of basic anisotropic models is poor and attempts to improve this accuracy with more complete models require difficult measurement techniques and complex computational representations.