T1

Henry Shu-hung Chung

East Gate (B1)

Professor Henry Shu-hung Chung is currently professor of the Department of Electronic Engineering and Director of the Centre for Smart Energy Conversion and Utilization Research, City University of Hong Kong.  His research interests include renewable energy conversion technologies, lighting technologies, and smart grid technologies.  He has authored six research book chapters, and over 300 technical papers including 140 refereed journal papers in his research areas, and holds 26 patents.  Prof. Chung is currently Chairman of Technical Committee on High-Performance and Emerging Technologies of the IEEE Power Electronics Society, and Associate Editor of the IEEE Transactions on Power Electronics, IEEE Transactions on Circuits and Systems, Part I: Fundamental Theory and Applications, and IEEE Journal of Emerging and Selected Topics in Power Electronics.

With advances in solid-state lighting, high brightness light emitting diodes (LEDs) have been widely adopted in general lighting applications, due to high luminous efficacy and long life expectancy.  We are now entering a new era of lighting history, shifting from traditional discharge lamps to solid-state lamps.  Thus, retrofit LED lamps for traditional lighting infrastructure would facilitate and accelerate market adoption of LED technologies.  More importantly, it is an environmentally-friendly solution, as it is unnecessary to change the lighting infrastructure.  In this tutorial, the presenter will deliver a talk related to retrofit LED lighting technology.  The presentation will start with the operating principle of typical discharge lamp ballasts.  Then, the requirements and considerations of driving LEDs with discharge lamp ballasts will be discussed.  Finally, a technology utilizing daisy-chain transformers for current balancing multiple LED strings in a high-power LED lamp will be presented.