Novel Core Designs to Miniaturise Passive Magnetic Components

Converter sizes are often dominated by passive magnetic components. Passive magnetic component sizes are in turn limited by electromagnetic saturation and thermal limits. This paper covers two modifications to the air gaps of tape wound amorphous magnetic cores, made available by the advancement of additive manufacturing with magnetic materials. These are modifying the width of the core at the air gap and moving the air gap to a different location in the core. The objective was to reduce the effect of fringing flux, and to overcome the issue of a high loss zone and thermal hot spot being generated at the air gap, situated under the windings. These modifications will reduce temperatures and thus allow for smaller components before thermal limits are reached. The changes this causes to inductance, flux density and losses are highlighted and discussed.