High-power-factor electronic ballast with intelligent energy-saving control for ultraviolet drinking-water treatment systems

Over the past few decades, ultraviolet (UV) water treatment has become widely recognized and accepted by regulatory agencies as a proven disinfection process. With the increased awareness of health concerns and water quality, UV disinfection is quickly gaining popularity in the consumer market as a safe, effective, and economical approach to disinfection. In order to disinfect properly, conventional UV water-treatment systems keep their light intensity at maximum level regardless of the operating condition; this will result in unnecessary energy waste along with lamp-life-span reduction. In this paper, a new design of highpower-factor low-cost electronic ballast with intelligent control for UV water-treatment system is proposed. For the purposes of energy saving, an intelligent-control algorithm is proposed to dim the luminance of the UV lamp according to the measured water flow rate and UV light intensity. Accurate knowledge of the characteristics of the UV lamps is essential for the ballast design. Therefore, an automatic identification system is also proposed in this paper to obtain the characteristic parameters, which are the dynamic and steady-state profiles of the UV lamps. Systematic design procedures are then presented accordingly. The proposed UV water-treatment system boasts the advantages, such as compactness, low cost, and energy saving, and is suitable for residential users. According to the experimental results, the energy-saving capability of the proposed system is better than 50%.