An introduction to nonlinear magnetics. Hysteresis

Abstract

This chapter is an introduction to nonlinear magnetic materials. Nonlinearity means that the relation between the magnetic field intensity and the magnetic induction is nonlinear. We also consider hysteresis, a behavior appearing in many ferromagnetic materials for which the magnetic induction at each particular point depends not only on its present magnetic intensity but also on the past history of its magnetic state. We introduce a well-known model for magnetic hysteresis: the classical Preisach model which is carefully described. We also address the identification problem of the Preisach operator for a specific ferromagnetic material by means of the so-called Everett function.