A Novel Linear Circuit For Current Equalization In Led Strings

Cláudio R. B. S. Rodrigues; Pedro S. Almeida; Guilherme M. Soares; Mateus F. Braga; Henrique A. C. Braga

doi:10.18618/REP.2013.3.11091117

Authors

Cláudio R. B. S. Rodrigues IFSEMG - Federal Institute of Education, Science and Technology of the Southeast of Minas Gerais – Campus Juiz de Fora
Pedro S. Almeida Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG
Guilherme M. Soares Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG
Mateus F. Braga Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG
Henrique A. C. Braga Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG

DOI:

https://doi.org/10.18618/REP.2013.3.11091117

Keywords:

current balancing, current equalization, LED string driving, LEDs, Linear equalization, solid state lighting

Abstract

This paper deals with the problem of current sharing in parallel strings of LEDs. As there is no guarantee that the string voltages are the same, some strategy for equalizing their currents must be used. This ensures that the luminous fluxes emitted by the strings are very similar. To address this issue it is proposed a small and simple linear topology that can be used on a number of series- associated LEDs, working as a constant current source for each string. Only four components are used in the arrangement, and a low dependence on transistor parameters is observed, ensuring good current regulation. Mathematical description and an analysis of the stability of the circuit are provided, as well as experimental results.

Downloads

Download data is not yet available.

Author Biographies

Cláudio R. B. S. Rodrigues, IFSEMG - Federal Institute of Education, Science and Technology of the Southeast of Minas Gerais – Campus Juiz de Fora

was born in Cataguases – MG in 1980. He received the B. S. and M. S. degrees from Federal University of Juiz de Fora, in 2006 and 2009 respectively. In 2012 he fulfilled the studies towards the obtaining of his Ph.D. degree. Since 2010 he is professor of the Federal Institute of Education, Science and Technology – Campus Juiz de Fora. His research interests are power electronics applied to lighting systems, public lighting, LEDs characteristics and HID lamps.

Pedro S. Almeida, Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG

received the B.S. degree in electrical engineering from the Federal University of Juiz de Fora (UFJF) in 2010, the master degree in 2012 at the same university and is currently pursuing the Ph.D. degree. Since 2008, he has been a researcher at the Modern Lighting Research Group (NIMO) of the School of Engineering. His main research interests are electronic converters for power factor correction, solid-state lighting, discharge lamps, electronic ballasts, modeling and control of converters.

Guilherme M. Soares, Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG

was born in Mercês, Brazil, in 1989. He received the B. S. degree in electrical engineering from the Federal University of Juiz de Fora (UFJF) in 2012 and is currently pursuing the M. S degree. Since 2010, he has been with in Modern Lighting Research Group (NIMO) at the same university, where he is currently a researcher. His main interests include electronic drivers for LED lighting, spectrophotometry, power factor correction and microprocessors applied to power electronic.

Mateus F. Braga, Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG

was born in Juiz de Fora, Brazil, in 1990. He is currently an undergraduate student in electrical engineering at the Federal University of Juiz de Fora (UFJF), Juiz de Fora, Brazil. Since 2012, he has been with the Modern Lighting Research Group (NIMO) at the same university, where he is currently a researcher.

Henrique A. C. Braga, Modern Lighting Research Group (NIMO) – Federal University of Juiz de Fora (UFJF) – Campus Universitário, Plataforma 5 – CEP 36036-030 – Juiz de Fora – MG

obtained the B.Sc. degree in Electrical Engineering from the Federal University of Juiz de Fora (UFJF) in 1982, and teaches in this institution since 1985. He earned the Master degree in Electrical Engineering from COPPE/UFRJ in 1988. In 1996 he attained the doctor degree (Dr. Eng.) in the same field at the Federal University of Santa Catarina, INEP/UFSC. He is currently an Associate Professor at UFJF, teaching in the undergraduate and postgraduate programs in Electrical Engineering, where he is mainly concerned with the subjects of Basic Electronics and Power Electronics. From 2005 to 2006, Prof. Braga has attended a postdoctoral stage at the University of Oviedo in the Spanish city of Gijon, Asturias. He is involved in activities related to Power Electronics, Efficient Lighting and Converters Applied to Renewable Energy. He is a member of SBA, IEEE and SOBRAEP.

References

J. Y. Tsao, "Solid state lighting: lamps, chips and materials for tomorrow," IEEE Circuits & Devices Magazine, vol. 20, no.3, pp. 28-37, 2004. https://doi.org/10.1109/MCD.2004.1304539 DOI: https://doi.org/10.1109/MCD.2004.1304539

G. Carraro, "Solving high-voltage off-line HB-LED constant current control-circuit issues," IEEE Applied Power Electronics Conference and Exposition (APEC), pp. 1316-1318, 2007. https://doi.org/10.1109/APEX.2007.357685 DOI: https://doi.org/10.1109/APEX.2007.357685

J. Arnold, "When the lights go out: LED failure modes and mechanisms," White Paper, Dfr Solutions, College Park, Margland, 2004.

E. F. Schubert, Light Emitting Diodes, Cambridge University Press, 2003.

On Semiconductor, AND8109-D - LED constant current source scheme: theory of operation, Application Note, 2003.

C. Correa, J. Garcia, C. Barriquello, A. Schittler, D. Camponogara and R. N. Prado, "Aplicação de espelhos de corrente no acionamento de LEDs de potência," Congresso Brasileiro de Automática (CBA), 2008. (In Portuguese)

Y. Hu and M. M. Jovanovic, "A novel LED driver with adaptive drive voltage," IEEE Applied Power Electronics Conference and Exposition (APEC), pp. 565-571, 2008. https://doi.org/10.1109/APEC.2008.4522777 DOI: https://doi.org/10.1109/APEC.2008.4522777

S. M. Baddela and D. S. Zinger, "Parallel connected LEDs operated at high frequency to improve current sharing," IEEE Industry Applications Conference/39th IAS Annual Meeting, vol. 3, pp. 1677-1681, 2004. https://doi.org/10.1109/IAS.2004.1348696 DOI: https://doi.org/10.1109/IAS.2004.1348696

C. Chiu and K. Chen, "A High Accuracy Current-Balanced Control Technique for LED Backlight," IEEE Power Electronics Specialists Conference (PESC), pp. 4202-4206, 2008.https://doi.org/10.1109/PESC.2008.4592615 DOI: https://doi.org/10.1109/PESC.2008.4592615

Texas Instruments, UCC28810EVM-003 - 110-W Multiple String LED Driver with Universal Line Input and PFC, User's Guide, 2009.

K. I. Hwu and S. Chou, "A simple current-balancing converter for LED lighting,"IEEE Applied Power Electronics Conference and Exposition (APEC), pp. 587-590, 2009. https://doi.org/10.1109/APEC.2009.4802717 DOI: https://doi.org/10.1109/APEC.2009.4802717

J. Zhang, L. Xu, X. Wu, Z. Qian. "A Precise Passive Current Balancing Method for Multioutput LED Drivers," IEEE Transactions on Power Electronics, vol. 26, no. 8, pp, 2149 - 2159, 2011. https://doi.org/10.1109/TPEL.2010.2104332 DOI: https://doi.org/10.1109/TPEL.2010.2104332

K. H. Loo, Y. M. Lai, C. K. Tse. "Design and Analysis of LCC Resonant Network for Quasi-Lossless Current Balancing in Multistring AC-LED Arrays," IEEETransactions on Power Electronics, vol. 28, no. 2, pp 1047 - 1059, 2013. https://doi.org/10.1109/TPEL.2012.2203149 DOI: https://doi.org/10.1109/TPEL.2012.2203149

C. Zhao, X. Xie, S. Liu. "Multioutput LED Driver With Precise Passive Current Balancing,"IEEE Transactionson Power Electronics, vol. 28, no. 3, pp 1438 - 1448, 2013. https://doi.org/10.1109/TPEL.2012.2210562 DOI: https://doi.org/10.1109/TPEL.2012.2210562

S. Choi, T. Kim. "Symmetric Current-Balancing Circuit for LED Backlight with Dimming," IEEE Transactions on Industrial Electronics, vol. 59, no. 4, pp 1698 - 1707, 2012. https://doi.org/10.1109/TIE.2011.2138112 DOI: https://doi.org/10.1109/TIE.2011.2138112

P. S. Almeida, J. M. Jorge, C. R. B. S. Rodrigues, G. M. Soares, D. P. Pinto, H. A. C. Braga, "A novel Method of Current Equalization in LED Strings Based on Simple Linear Cicuit," Proc. of IEEE International Symposium on Industrial Electronics (20TH IEEE ISIE). GdaĔsk, Poland. June, 2011. https://doi.org/10.1109/ISIE.2011.5984139 DOI: https://doi.org/10.1109/ISIE.2011.5984139

Osram Opto Semiconductors, LUW W5PM Golden Dragon Oval Plus, Datasheet, 2010.

Amtex Electronics, Application Note: 1 - LED Power Supplies, Common LED Configurations, Application Note, 2009.

D. L. Schilling and C. Belove, Electronic Circuits: Discrete and Integrated, McGraw Hill International Edition, 1980.

T. F. Bogart Jr., Electronics devices and circuits, Vol. 1, 3rd edition. Makron Books Ltd, 2001.

General Semiconductors, BC546 thru BC549 - Small Signal Transistors (NPN)," Datasheet, 2009.

P. S. Almeida, J. M. Jorge, D. Botelho, D. Pinto and H. Braga, "Proposal of a Low-Cost LED Driver for a Multistring Street Lighting Luminaire", IEEE Industrial Electronics Conference (IECON 2012), Montreal, October, 2012. https://doi.org/10.1109/IECON.2012.6389476 DOI: https://doi.org/10.1109/IECON.2012.6389476