Buck-Boost Combined with Active Clamp Flyback Converter for PV Power System

This paper presents an LED lighting system with PV sources. The circuit of the proposed system adopts buck-boost converter associated with flyback converter to charge battery and to drive an LED lighting system. In this research, buck-boost converter is used as a charger for charging battery, and flyback converter with active clamp circuit is adopted to drive the 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 count, 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 83% under full load at driving the LED lighting. Experimental results obtained from a prototype with output voltage of 10 V and output power of 20 W have verified its feasibility.