Modelling of dynamic losses in soft ferrite cores

In this paper a time domain model of the dynamic behavior of ferrite cores is implemented and discussed. This model is based on the magnetic field decomposition in three parts dealing with the static anhysteretic magnetization, the static hysteretic magnetization and the dynamic magnetization processes. These three components are depending on the magnetic induction values and derivative in time domain by means three functions properly identified. In particular, the capability of the model for power losses prediction is discussed, also in comparison with the classical approaches defined on both frequency domain and time domain by Steinmetz. The model parameters are identified for a suitable Mn–Zn ferrite inductor with toroidal core, and the reliability of the method for the prediction of the magnetization processes, under sinusoidal and not sinusoidal excitations, is assessed for the typical work frequency range of magnetic components in power electronics devices.