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Implementation of High Power LED Driving Source with High Efficiency and High Power Factor for Indoor Illumination

With the increasing awareness about environmental protection, energy conservation, and carbon reduction, High Power Light-Emitting Diodes (LEDs) have gradually replaced conventional lighting sources. This study employed High Power LED to develop an indoor illumination system with high power factor and high efficiency. The LED driver adopted a boost-buck converter combined with a forward-flyback converter; moreover, a hybrid control technique including energy-regenerative snubber, primary-side sensing, and quasi-resonant switching was employed to reduce circuit devices and improve efficiency. In addition, a digital signal processor (DSP) was used as the core of system control, which enabled the system to automatically adjust brightness and color temperature by applying a sequential pulse width modulation (PWM) scheme and an optical sensor to the dimmer. Finally, a system prototype was built up, and the electrical and optical characteristics were tested. The results confirmed the feasibility of the proposed system.