Virginia Tech Intellectual Properties, Inc.

Chao Fei

Fred C Lee

Qiang Li

Bin Li

Weiyi Feng

Hongfei Wu

Three-phase interleaved LLC and CLLC resonant converters, with integrated magnetics, are described. In various examples, the primary sides of the phases in the converters rely upon a half-bridge configuration and include resonant networks coupled to each other in delta-connected or common Y-node configurations. The secondary sides of the phases can rely upon a full-bridge configurations and are coupled in parallel. In one example, the transformers of the phases in the converters are integrated into one magnetic core. By changing the interleaving structure between the primary and secondary windings in the transformers, resonant inductors of the phases can also be integrated into the same magnetic core. A multi-layer PCB can be used as the windings for the integrated magnetics.

Interleaved converters with integrated magnetics

A matrix transformer particularly suited to large voltage step-down, high current applications achieves increased good current sharing uniformity or air gap and electrical characteristics and reduced or eliminating termination losses, core losses and winding losses with a unitary magnetic core structure featuring sheets of magnetic material and a two-dimensional array of pillars on which windings, oriented in opposite directions on pillars that are adjacent in orthogonal directions, can be formed or placed comprising metallization on or embedded in a printed circuit board (PCB) structure. Magnetic flux density is reduced by at least one-half by dividing the magnetic flux in each pillar into two paths of increased width in the sheets of magnetic material. Magnetic flux density may be further decreased and flux uniformity improved by extending the sheets of magnetic material beyond a periphery defined by the pillar array.

Matrix transformer and winding structure

A resonant power converter is disclosed with a driving circuit generating a switching signal connecting power to a resonant tank circuit, with a voltage monitoring circuit measuring a voltage output and a load current. A micro-controller is operable with a control circuit for multiple step sampling with the switching signal at a switching frequency to settle the resonant circuit determined from the voltage output and load current. A fast load transient response at a high frequency with the resonant circuit provides the multiple step sampling to ensure enough time for micro-controller to calculate. Optimal trajectory control facilitates a burst mode of high frequency with the resonant circuit using adaptive multiple step sampling for an on-time to extend the burst operation range. A soft start-up process uses the micro-controller processing in multiple stages.

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Blacksburg, VA, United States of America

Chao Fei