Design and evaluation of a reconfigurable stacked active Bridge dc/dc converter for efficient wide load-range operation

This thesis presents the design and implementation of a step-down soft-switched dc-dc converter based on an active bridge topology which overcomes some of the limitations of the conventional dual-active bridge (DAB). The topology comprises a double-stacked bridge inverter, coupled to a recongurable rectifier through a special three-winding leakage transformer. The converter can run in a low power mode that greatly increases light-load efficiency by reducing core loss and extending the zero-voltage switching (ZVS) range. The converter is implemented with a single compact magnetic component, providing power combining, isolation, and energy transfer inductance. The theory of the converter and its various operating modes, referred to in this thesis as the Double-Stacked Active Bridge converter, is also explored, and a magnetic model of the special three-winding transformer and leakage inductance is presented. The target application is for 380 V dc distribution systems for data centers, where the converter operates for the majority of the time at the nominal input voltage, but must have high eciency over a wide load range. A 175 kHz, 300 W, 380 V to 12 V prototype converter achieves 95.9% efficiency at full load, a peak efficiency of 97.0%, an efficiency above 92.7% down to 10% load and an efficiency above 79.8% down to 3.3% load.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2016

Author dc:creator

• Abramson, Rose (Rose A.)

Advisor dc:contributor.advisor

• David J. Perreault.

• Electrical Engineering and Computer Science.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/112817

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/112817