Frequency dependent model of ferromagnetic hysteresis for time domain analysis of cable shields

This paper describes a simple numerical technique for time-domain analysis of ferromagnetic tubular shields taking into account the effects of hysteresis. The frequency dependent Jiles model of ferromagnetic hysteresis and the finite difference technique are used to solve the field distribution inside the ferromagnetic shield in time-domain. The effects of the ferromagnetic hysteresis on the shielding properties are illustrated by several examples. The concept of dynamic permeability is discussed and comparison with more simplified modeling of ferromagnetic materials is presented.