Reduction of power loss in easy-plane FeSi soft magnetic composite under a weak bias magnetic field

Abstract

This paper investigates the impact of a weak bias magnetic field (Hbias) along the easy magnetization plane direction on the power loss of easy-plane Fe-6.5 wt%Si (FeSi) soft magnetic composite (SMC). The results demonstrate that the power loss (Pcv) decreases by 18 % when the Hbias is 11.6 kA/m. Furthermore, it is found that the reduction in Pcv is not only attributed to decreases in hysteresis loss but also involves a decrease in excess loss. The causes of hysteresis loss and excess loss reduction are further investigated and it is found that the effect of the Hbias on the magnetization state plays an important role in the reduction of hysteresis loss. Additionally, the decrease in excess loss can be attributed to the reduction in local eddy current losses caused by non-uniform domain wall motion. These findings provide valuable insights for achieving high-frequency (MHz), high-efficiency, and miniaturized power electronic devices.