A comparative analysis of core material and gap sizing effect on the high-power inductor design

Abstract

Air-gaps are used in the core structures of inductors, which are used as energy-storing components in power electronic circuits, to keep them away from saturation. As a result, changes in the electrical and magnetic parameters of the inductor are inevitable due to air-gaps. Depending on the electromagnetic properties of the core material used, the saturation current of the inductor and the change in inductance values are behaviors that need to be determined carefully. In this study, saturation flux values and inductance change graphs of high-power and medium-frequency inductors designed with soft magnetic core materials such as amorphous, nanocrystalline and 6,5%SiFe and using air-gaps in their core structures were comparatively analyzed. Although the amorphous core inductor exhibited better electrical performance at the relevant operating frequency and current values, according to the electromagnetic analysis made with the FEA software, the high magnetostriction coefficient of the amorphous material should be considered in applications that may be affected by vibration (applications of approximately 4 kHz and above). Additionally, evaluations regarding core losses and core dimensions are presented together with the results of comparative analyses.