Personnel

FICs - Prof. Wing-Hung Ki, Prof. Philip K. T. Mok and Prof. Johnny K. O. Sin

Description

Fluorescent lamps have higher luminous efficiency (80 lumens/W) than incandescent lamps (20 lumens/W). Most existing fluorescent lamps employ electromagnetic ballasts for control, which ballasts operate at double of the line frequency, and require bulky magnetics. Yet lamps operate more efficiently at high frequencies, e.g., 30kHz, by 20% to 25%, require smaller magnetics, and can use electronic ballast for control. Advance control features include dimmability for many applications and for energy saving. A power-factor-correcting front end is also needed to reduce harmonic distortion of the main power line. Discrete component realizations will be bulky and not be cost effective and an integrated circuit solution is needed. To further reduce cost and size, smart-power ICs should be developed such that the controller can be fabricated on the same chip as the driver circuit.

This research is intended to develop and realize an efficient dimmable lighting system for commercial and industrial applications using fluorescent lamps. Major research issues include fluorescent-lamp modeling which incorporates dynamic negative resistivity for hand-analysis, and system modeling for efficiency and stability considerations. Topologies for power-factor correction will be compared for performance. High-voltage and high-speed power devices are to be developed and optimized for the smart-power IC approach, and a prototype of the lighting system will be built and evaluated in demonstrating the concept of the study.

Source: RGC | ITF