Loss Characterization and Calculation of Nanocrystalline Cores for High-Frequency Magnetics Applications

The loss density of the nanocrystalline magnetic material is experimentally characterized up to 500 kHz and above 1 Tesla in this paper. B-H hysteresis magnetization curves and loss density of the material under various operating temperatures up to 150degC are measured and presented. The core preparing effect on magnetic loss density is also identified by experiments, which provides information necessary to practical magnetic designs. A new empirical core loss calculation method, flux-wave-form-coefficient Steinmetz equation, is proposed and verified for the nanocrystalline material under resonant operations, which are often employed in high-frequency power converter applications. The proposed approach is either more accurate or easier to use than the previous methods.