PV power system using buck/forward hybrid converters for LED Lighting

This paper presents an LED lighting system with a PV source. The circuit structure of the proposed system adopts buck converter combined with forward converter. In this research, buck converter is used as a charger for charging battery, and forward converter with active clamp circuit , which can recover leakage inductor energy and reset magnetizing energy stored in the transformer, is adopted to drive LED lighting. To simplify the circuit structure, switches of two converters are integrated with a synchronous switch technique. With this approach, the proposed system has several merits, which are a less component counts, lighter weight, smaller size and higher conversion efficiency. Compared with the conventional converter with hard-switching circuit, the proposed one can improve conversion efficiency of 5% and achieve efficiency about 82% under full load when the proposed system is operated in the driving LED condition. Experimental results obtained from a prototype with the output voltage of 10 V and output power of 20 W have been implemented to verify verified its feasibility.