Development and Optimization of a Hybrid Coupled Inductor Pair for High Power and High Density Multi-Phase DC-DC Converters

High power DC-DC converters are widely used in electric vehicle drive trains, energy storage systems, fast chargers, and photovoltaic converter systems, etc. To improve the power density and the efficiency of DC-DC converters, a hybrid coupled inductor pair with different core materials is proposed in this paper. A systematic investigation of DC choke configurations and designs based on a multi-objective optimization approach is presented. A combined low loss core material and high saturation core material are adopted for the proposed coupled inductor pair. A 160A/750V prototype based on the proposed optimal solution was constructed and tested, which demonstrated significant performance improvement over the standard uncoupled inductors, including 51% of volume, 48% of weight and 63% of power loss reductions.