Authors : Kwang-Seok Song, Gwang-Cheol Song, Jung-Hwan Lee, Seong-Mi Park and Sung-Jun Park
Abstract: The development of high efficiency electric light bulbs and high efficiency power converters are drawing high interests in order to realize high efficiency lighting systems. Particularly, high efficiency power converters are showing the trend of being embodied through the reduction of switching losses. Representative methods for reducing switching losses are classified into 2 general categories: reduction of excessive switching losses by soft switching topology and reduction of switch conduction losses by the topology that can decrease the number of conduction switch elements. Particularly, an LED equivalent circuit is expressed with a capacitance of constant capacity and a zener diode that has the characteristics of resistance and threshold voltage. Accordingly, since LED load is different from conventional loads, the embodiment of a high efficiency power converter for operating LED demands a DC/DC topology that is suitable for the characteristics of LED load. This research proposes a new high efficiency DC/DC converter topology for LED street-lamps. The proposed DC/DC converter employed secondary resonance to achieve soft switching when the switch is turned on/off. In addition, it was possible to reduce switch conduction losses by configuring the resonance circuit with a current loop that has a single semiconductor element. Simulation experiments using Psim were carried out to verify the performance of the DC/DC converter and the result confirmed its excellence.
Kwang-Seok Song, Gwang-Cheol Song, Jung-Hwan Lee, Seong-Mi Park and Sung-Jun Park, 2017. Soft Switching Technique of a Secondary Resonant Buck Converter. Journal of Engineering and Applied Sciences, 12: 6675-6683.