The objective of the research is to develop a cost-effective high-power bi-directional dc/dc converter with low total-device ratings, reduced system parasitic effects, and a wide input/output range. Additional objectives of the research are to develop a small-signal model and control methods, and to present performance characterizations. Device stresses in the proposed topology are controlled to maintain minimal levels by varying the duty ratio and phase-shift angle between the primary and the secondary bridges, which results in a low total-device rating, when compared to conventional bi-directional dc/dc topologies. In the proposed topology, soft switching, which reduces power loss, can be realized under specific operating conditions. When the condition that causes minimal device stress is satisfied, zero-voltage switching (ZVS) can be obtained. In the research, ZVS capability is explored for a wide range of voltage conditions as well as for the minimal device-stress condition. The performance characterization includes verifying the soft-switching regions and power-loss estimation. Another part of the thesis is the controller design of the converter. Small-signal models and feedback controllers are developed, and the controllers are experimentally validated. Because in the isolated high-frequency converters, transformer saturation is an important issue, a method to prevent transformer saturation is proposed and experimentally validated.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/49010 |
| Date | 11 May 2012 |
| Creators | Han, Sangtaek |
| Contributors | Divan, Deepakraj M |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Dissertation |
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