The paper presents an advanced modeling technique of ferromagnetic cores, entirely based on Maxwell’s theory. Our models answer to common modern applications of electrical engineering. They use nonlinear electrical equivalent diagrams, easy to built according to the core geometry (including air-gaps) and ferromagnetic material characteristics. The core model is compatible to be included in the entire circuit model, being suitable for the time-domain analysis. The circuit analysis provides complete information on any working parameters of the magnetic core (as the main and leakage time-domain magnetic fluxes, position and shape of minor magnetizing loops, instantaneous and mean eddy current losses, dynamic permeabilities, dynamic inductances, etc.), as well as of other parts of the analyzed circuit.

Keywords: Ferromagnetic core, Eddy current losses, Modeling, Time-domain simulation, SPICE subcircuit.