New Geometry Integrated Inductors in Two-channel Interleaved Bidirectional Converter

A new geometry of integrated inductors for twochannel interleaved bidirectional converter is presented in this paper. The new geometry module integrates two individual inductors by stacking three I-cores. The middle I-core provides a shared flux path with low reluctance which uncouples the two inductors.

The air gaps are constructed by separating the I-cores using copper foil windings with well-defined thickness. In this work, inverse connection and direct connection for the two integrated inductors have been analyzed. For the inverse connection, a unique saturation behavior in the middle I-core has been shown.

The integrated inductors with new geometry make it possible to build low-profile, low-cost, flexibility DC/DC converters, and it can be extensively designed for low-voltage and high-current required by modern digital applications. Experiment results obtained from a 48V-12V 30A two-phase interleaved buck converter, demonstrates the difference in the inverse connection and the direct connection.

Both efficiencies are above 91% from half to full output current.