Feature Analysis on B–H Curves of Dust Cores Under the Application of DC Bias Field

To realize high-efficiency power converters, it is very important to reduce the loss of passive magnetic components of transformers and inductors in high-frequency regions. Iron loss behavior under a dc bias field is crucially important to characterize inductor performance, but it has not been well analyzed. In this study, the iron loss behavior of a Sendust dust core has been analyzed in relation to the change in the
$B$
–
$H$
curve shape using principal component analysis (PCA). The iron loss monotonically decreases with increasing the dc bias field accompanying the reduction of permeability and slight asymmetric change in the
$B$
–
$H$
curve shape. PCA can extract featured quantities of these changes in
$B$
–
$H$
curve shape. Consequently, it is revealed that the curvature of the
$B$
–
$H$
curve changes its polarity with increasing the dc bias field, and this behavior has a strong relationship with the reduction of iron loss.