High voltage gain soft switching full bridge interleaved Flyback DC-DC converter for PV applications

This paper introduces a soft switching full bridge interleaved Flyback DC-DC converter with high gain. Half bridge Flyback converter will cause many problems in comparison with full bridge structure such as high-volume split capacitors and complex control for charging and discharging them for proper operation. By applying full bridge interleaved structure, the output current ripple can be reduced, and more power can be supplied to the load. Besides, the greatest way for reducing the weight, size and volume of the converter is applying soft switching methods. As well, the switching frequency is increased to boost the power density. To reduce switching losses, clamp circuit with a passive lossless snubber is applied in the suggested full bridge interleaved Flyback converter. In the proposed topology, soft switching conditions for all semiconductor elements are achieved by the passive snubber. It absorbs the stored energy in parasitic elements at the turn-off instant. The main superiority of the proposed topology in comparison with many other similar converters is that its passive snubber is load independent. A 110 W prototype of the topology is implemented. The experimental results confirm the aforementioned advantages of the converter such as high efficiency (92% at full load) and high gain (23.2).