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 150 $^{\circ}$C 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-waveform-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.