A minimum loss inductor design for an actively clamped resonant DC link inverter

The actively clamped resonant DC link inverter (ACRLI) is a well established soft-switching topology, however its resonant inductor is problematic, and is often cited as its primary stumbling block. This paper presents the design and fabrication of a very-low-loss high frequency ACRLI optimised inductor. The low-loss design was obtained by minimising the hysteretic and eddy current loss of the inductor's ferrite cores, and the conduction loss of the Litz wire windings. The inductor was built, including custom Litz wire, with a resulting loss of less than 16 watts, or 0.16% of the total 10 kW inverter throughput. This represents a significant improvement in the current state of the art in ACRLI inductor design and extends the applicability of the ACRLI topology.