Nonlinear modeling of magnetic materials for electromagnetic devices simulation

Abstract

Magnetic materials are broadly use in electrical engineering applications, due to its high permeability that allows increasing magnetic flux. Analyzing systems containing these magnetic cores is complex due to the nonlinear behavior of the magnetic material. This nonlinear behavior can be represented by the magnetization curve and by the hysteresis phenomenon curve. In this work, only magnetization curve is modelled and shows flow variations by varying the magnetic field. For higher values of magnetic field, there is not a present considerable variation of magnetic flux. At this stage, the magnetic material or the core reaches its saturation. In this work, simple mathematical models represent nonlinear behavior of magnetic material in order to be used in circuit simulation and inductor design. Linearized, polynomial and hyperbolic models are used. The linearized model approaches experimental BH curve for linear segments. The polynomial model approaches the curve by polynomial equation and the hyperbolic model approaches the curve using a hyperbolic equation. For models implementation is needed the experimental BH curve. An RL circuit is used. Equations of the electric circuit, magnetic flux and the material model are coupled and solved. To validate, simulation and experimental voltage and current are compared.