Excitation-Dependent Temperature Behavior of the Quasi-static Hysteresis Loss Energy Density of N87 Ferrite Material

Abstract:
This paper presents a study of the temperature behavior of the quasi-static hysteresis loss energy density of the ferrite material N87. First, the material data is measured by use of a small toroidal core with the volt-amperometric method. To adjust the temperature of the device under test, the core is dived into an oil bath of a temperature calibrator. The excitation frequency of 1 kHz ensures the quasi-static behavior. The measurements are performed for various excitation levels of the magnetic flux density. Second, the measured data is approximated by various fit formulas. A model that uses a polynomial fit of the temperature dependence for different excitation levels of the magnetic flux density shows the most promising results. Additionally, the model uses a further fit of the polynomial coefficients. This allows the prediction of the loss energy density for a wide temperature range by using only a few parameters.