Title :
Single-stage electronic ballast with dimming feature and unity power factor
Author :
Wu, Tsai-Fu ; Yu, Te-Hung ; Chiang, Meng-Chian
Author_Institution :
Dept. of Electr. Eng., Nat. Chung Cheng Univ., Chia-Yi, Taiwan
fDate :
5/1/1998 12:00:00 AM
Abstract :
Analysis, design, and practical consideration of a single-stage electronic ballast with dimming feature and unity power factor are presented in this paper. The proposed single-stage ballast is the combination of a boost converter and a half-bridge series-resonant parallel-loaded inverter. The boost semistage working in the discontinuous conduction mode functions as a power factor corrector and the inverter semistage operated above resonance are employed to ballast the lamp. Replacing the lamp with the plasma model, analysis of the ballast is fulfilled. The dimming feature is carried out by pulse-width modulation (PWM) and variable-frequency controls simultaneously. The proposed single-stage ballast is suitable for applications with moderate power level and low-line voltage while requiring a high-output voltage. It can save a controller, an active switch and its driver, reduce size, and possibly increase system reliability while requiring two additional diodes over a conventional two-stage system. A prototype was implemented to verify the theoretical discussion. The hardware measurements have shown that the desired performance can be achieved feasibly
Keywords :
DC-DC power convertors; PWM power convertors; bridge circuits; discharge lamps; invertors; lamp accessories; optical variables control; power factor correction; resonant power convertors; boost converter; boost semistage; dimming; discontinuous conduction mode; gas discharge lamps; half-bridge series-resonant parallel-loaded inverter; high-output voltage; inverter semistage; low-line voltage; plasma model; power factor corrector; pulse-width modulation; reliability increase; single-stage electronic ballast; unity power factor; Electronic ballasts; Lamps; Plasma applications; Pulse width modulation; Pulse width modulation inverters; Reactive power; Resonance; Space vector pulse width modulation; Switches; Voltage;
Journal_Title :
Power Electronics, IEEE Transactions on