The nonlinear magnetic core model used in spice plus

The SPICE PLUS simulation program offers circuit designers full capability for simulating magnetic cores used in power supplies and in other power design circuits. This paper is an overview of the model, its capabilities, and application. The magnetic model defines both major and minor hysteresis loops, which are derived from the dynamic relationship between magnetic flux density and magnetic field strength in cores. A model for cores with gaps has been implemented and its effects on the magnetization curves is explained. Finally an example of accurate simulation is given that shows the importance of modeling the core's nonlinear effects.