An efficient procedure for modeling complex hysteresis processes in ferromagnetic materials

A simple mathematical formalism for describing arbitrary hysteresis processes is presented. The information required to apply this formalism to a given magnetic material can be obtained with relatively little effort from experimental hysteresis curves such as normal loops or, in special cases, from just the initial curve. The basic physical model is that of Preisach. A more convenient, less widely known, treatment of this modes by Everett to which we have applied magnetic symmetry constraints leads to a succinct description of hysteresis processes. We have applied this procedure to calculate losses in nonoriented electrical steel laminations. The fully non-linear electromagnetic field equations were solved on the computer for this simple geometry with no restrictions on the hysteresis paths. The calculated losses agreed at the 5% level with experimental losses for a wide range of frequencies and inductions.