Numerical Modeling of Magnetic Characteristics of Ferrite Core Taking Account of Both Eddy Current and Displacement Current

Ferrite cores are widely used in transformers and inductors, etc. for high frequency electronic devices because of high magnetic permeability and low conductivity. In the magnetic field analyses of such magnetic devices using a ferrite core, the frequency-domain analysis is often carried out using measured effective complex permeability under different frequencies. However, the harmonics caused by the magnetic nonlinearity of the ferrite core cannot be evaluated by using the frequency-domain analysis. To carry out the time-domain analysis of ferrite core taking account of the nonlinearity of the core, the modeling method of the effective complex permeability characteristics, which decreases in high frequency region due to dimensional resonance, should be established. In this paper, a simple finite element magnetic field analysis model taking account of eddy current and displacement current is proposed. The suitable conductivity and permittivity which can realize the effective complex permeability is investigated by using the catalogue data of a toroidal MnZn ferrite core.