We present a new field-extrema hysteresis loss model (FHM) for high-frequency ferrimagnetic materials, along with a parameter identification procedure. The model does not involve solving an ordinary differential equation (ODE) and is asymmetric in that it works well under dc bias conditions. In the proposed model, the loss calculations are based on the extrema values of the fields. The model includes the effects of magnetic saturation as well as frequency effects. The model is comparable in accuracy to the ODE-based Jiles-Atherton model, but retains the convenience and computational efficiency of an empirical model. We demonstrate a procedure to characterize the model parameters using the Jiles-Atherton model. We compare magnetic hysteresis loss calculated by our new model with a full time-domain solution, as well as an empirical model, for a sample high-frequency ferrite. We demonstrate the use of the model, and validate the model, by calculating magnetic loss in an EI core inductor operating as the filter inductor in a buck converter. The model and identification procedure are being endorsed as a useful framework for computing magnetic loss in the context of automated magnetic device design.


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Differential equations, ferrites, magnetic hysteresis, Parameter estimation

Date of this Version

January 2008



Published in:

IEEE Transactions on Magnetics 44,7 (2008) 1728-36;



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