Buck-boost converter associated with active clamp forward converter for PV power system

This paper presents an LED lighting system with a PV source. The circuit structure of the proposed system adopts buck-boost converter associated with forward converter. In this research, buck-boost converter is used as a charger for charging battery, and forward converter with active damp circuit is adopted to drive LED fighting, and to respectively recover and reset energies stored in leakage inductor and magnetizing inductor of the transformer. 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 6% and achieve efficiency about 82% under full load when the proposed system is working 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 verified its feasibility.