DocumentCode :
1476395
Title :
PWM Series Dimming for Slow-Dynamics HPF LED Drivers: the High-Frequency Approach
Author :
Gacio, David ; Alonso, J. Marcos ; Garcia, Jorge ; Campa, Lidia ; Crespo, Mario J. ; Rico-Secades, Manuel
Author_Institution :
Dept. of Electr. Eng., Univ. of Oviedo, Gijon, Spain
Volume :
59
Issue :
4
fYear :
2012
fDate :
4/1/2012 12:00:00 AM
Firstpage :
1717
Lastpage :
1727
Abstract :
This paper deals with the capability of pulse width modulation (PWM) dimming operation added to the high-power factor-integrated buck-flyback converter (IBFC), which was developed in previous works for LED lighting applications. First, the two main dimming techniques will be introduced, namely, analog dimming and PWM dimming. Then, the three main PWM dimming schemes found in the literature, that is, enable dimming, series dimming, and parallel dimming, will be briefly discussed. Afterwards, the IBFC topology will be tested performing both analog and enable dimming. In addition, a new proposal is introduced: the high-frequency series PWM dimming technique, which overcomes all the challenges faced when developing PWM dimming capabilities in low slew-rate constant-current fixed-frequency-controlled converters and offers all the advantages of PWM dimming over analog dimming while maintaining good efficiency. The proposed dimming-technique control loop, as well as the laboratory tests, will be presented, discussed, and compared to analog dimming and PWM dimming, showing satisfactory results in terms of dimming ratio, input current total harmonic distortion (THDI), and power factor.
Keywords :
PWM power convertors; driver circuits; light emitting diodes; lighting; power factor; LED lighting; PWM series dimming; analog dimming; enable dimming; high-frequency series PWM dimming technique; high-power factor-integrated buck-flyback converter; low slew-rate constant-current fixed-frequency-controlled converters; parallel dimming; pulse width modulation dimming; slow-dynamics HPF LED drivers; total harmonic distortion; Frequency conversion; Light emitting diodes; Lighting; Pulse width modulation; Topology; Voltage measurement; Industrial power systems; light-emitting diodes (LEDs); lighting control; power electronics;
fLanguage :
English
Journal_Title :
Industrial Electronics, IEEE Transactions on
Publisher :
ieee
ISSN :
0278-0046
Type :
jour
DOI :
10.1109/TIE.2011.2130503
Filename :
5735216
Link To Document :
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