A high-frequency electronic ballast with auto-tracking control was proposed to operate the metal halide lamps at a specific frequency free from acoustic resonance. In case the acoustic resonance should happen, the operating frequency is changed step by step with the auto-tracking control, until the lamp is operated at a frequency with stable operation.
The electrical characteristics of the lamps are first investigated. Based on the investigated results, a detection circuit is designed to identify the occurrence of acoustic resonance. With the auto-tracking control, the Class-D half-bridge series-resonant inverter can be adopted for the high-frequency electronic ballast to achieve high efficiency and high power density. The control strategy of auto-tracking is practically realized by a single-chip microprocessor. The proposed approach is implemented on a 70 W test lamp with an operating frequency range from 20 kHz to 30 kHz. To regulate the lamp power at its rated value, a buck-boost converter is used as a pre-regulator, which serves also as a power-factor-corrector to achieve a high power factor at the input line.
Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0619103-193218 |
Date | 19 June 2003 |
Creators | Huang, Chun-Kai |
Contributors | Jia-You Lee, Tsorg-Juw Liang, Chin-Sien Moo, Chih-Chiang Hua, Jsair-Rong Chen |
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-0619103-193218 |
Rights | restricted, Copyright information available at source archive |
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