Computation of the Preisach distribution function based on a measured Everett map

Modeling the hysteresis behavior of soft magnetic materials based on Preisach theory, requires a Preisach distribution function characterising the material. Although it is possible to obtain all the data for a classical Preisach model from experimental first-order curves, obtaining the Preisach distribution function by differentiating this data twice leads to large errors and even to negative values in the distribution function, This work reports on how to avoid these errors in the Preisach function when it is computed starting from measured data. Measured BH-loops are arranged into an Everett function, which is then corrected in order to serve as a basis for the Preisach distribution function. The computation method is tried out on a nonoriented, a grain oriented and an iron-powder material.