A current balancing scheme with high luminous efficiency for high power LED lighting

Xiaohui Qu, Siu Chung Wong, Chi Kong Tse

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

4 Citations (Scopus)


The current imbalance in driving LED strings will cause fast degradation or even failure in some LEDs that should be avoided in LED applications. This paper presents a current balancing method based on the pulse-width modulation of a common bus voltage to each LED string to achieve the intended averaged current. For the balance of a common averaged current, a small duty cycle will necessitate a large LED turn-on current amplitude, which may cause temporal overheat and low luminous efficacy of LEDs. An optimal feedback control scheme is proposed to maximize the duty cycles and minimize the bus voltage. As a result, at lease one of the LED string is operating at a unity duty cycle. The analysis, implementation and verification are detailed in this paper.
Original languageEnglish
Title of host publicationProceedings, IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society
Number of pages6
Publication statusPublished - 1 Dec 2013
Event39th Annual Conference of the IEEE Industrial Electronics Society, IECON 2013 - Vienna, Austria
Duration: 10 Nov 201314 Nov 2013


Conference39th Annual Conference of the IEEE Industrial Electronics Society, IECON 2013


  • current balancing
  • dimming
  • high power LEDs
  • luminous efficacy

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this