Design Flexibility of a Modular Low-Loss High-Frequency Inductor Structure

Abstract

Miniaturization and efficiency of power electronics are limited by magnetic components, which are difficult to scale to small size and high frequency (HF). Inductor structures using field shaping, quasi-distributed gaps, and modular construction can achieve low loss at HF (3-30 MHz) without litz wire. For widespread adoption though, these structures must be shown to remain effective across a wide design range and be economical to manufacture. This article investigates the design flexibility of one such previously proposed inductor structure with a modified pot core and demonstrates that this structure can provide excellent performance for a wide range of inductance and power handling requirements using only a few sets of manufactured core pieces. The core pieces used in the modified pot core structure can be scaled by 4× in volume, compared to roughly 2× for conventional core families, and still achieve high performance over a wide design space. Moreover, this approach can achieve about half the loss of conventional designs at HF and, unlike conventional core sets, can provide a range of low-loss form factors with a single family of components. The proposed inductor structure and design approaches, thus, offer new opportunities in the practical production of low-loss HF inductors.