Magnetic Material Selection for High Power High Frequency Inductors in DC-DC Converters

• Main Authors: Rylko, M.S., Hartnett, K.J., Hayes, J.G., Egan, M.G.
• Format: Conference Proceeding
• Language: English
• Subjects: Aerospace industry; Amorphous magnetic materials; Building materials; Conducting materials; DC-DC power converters; Frequency conversion; Inductor size analysis; Inductors; Inorganic materials; Magnetic materials; Silicon
• ISSN: 1048-2334; 2470-6647
• DOI: 10.1109/APEC.2009.4802955

Dc-dc converter size and efficiency are driving factors in industrial, aerospace and automotive applications. Thus, optimal component selection is essential for a compact design. The inductor often appears as the converter's largest component. This paper presents analytical and experimental comparisons of the magnetic materials used in a practical design. The investigation is concerned with magnetic material selection for a dc-dc power inductor in the medium (20 kHz) to high (150 kHz) frequency range and the low (1%) to high (220%) current ripple range. The materials under investigation are iron-based amorphous metal, silicon steel, nanocrystalline, ferrite, powdered iron and gap-less powder materials. A newly developed silicon steel material from JFE-Steel Co. is presented. A novel material comparison which includes thermal conductivity and saturation capability is proposed. The area product analysis for material comparison is presented for 10 kW dc-dc inductor design examples. The variation of core power loss with dc-bias is experimentally investigated for different materials. A 1.25 kW half-bridge dc-dc converter is used in experimental validation.