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

Abstract

To realize high efficiency power converters, it is very important to reduce loss of passive magnetic components of transformers and inductors in high frequency region. 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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> 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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve shape. PCA can extract featured quantities of these change in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve shape. Consequently, it is revealed that the curvature of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve changes its polarity with increasing the DC bias field, and this behavior has a strong relationship with the reduction of iron loss.