This thesis presents a single-stage high-power-factor electronic ballast for metal halide lamps. The proposed ballast integrates a buck-boost converter, a buck converter and a full-bridge inverter into a single power conversion circuit. The buck-boost converter is designed to be operated at the discontinuous conduction mode (DCM) with a constant duty ratio at a fixed switching frequency to provide a constant lamp power and to achieve a high power factor for a given ac input voltage. The full-bridge inverter supplies a square-wave current for the lamp at a low frequency the same as the line frequency to avoid acoustic resonance. For the universal input voltage ranged from 90 V to 264 V, the lamp remains at the rated power by controlling the duty-ratio of the buck converter.
The circuit operation is analyzed in detail to derive the design equations. An electronic ballast for 70 W lamps is designed and tested. Computer simulations and experimental measurements are provided to verify that the proposed ballast has the merits of a nearly unity input power factor, a high efficiency greater than 82 % and can drive the lamp at a constant power.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0720109-134315 |
| Date | 20 July 2009 |
| Creators | Yang, Chung-sheng |
| Contributors | Hung L. Cheng, T. J. Liang, T. F. Lin, Jia-You Lee, C. S. Moo |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720109-134315 |
| Rights | restricted, Copyright information available at source archive |
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