Non-isolated interleaved high step-up converter with reduced voltage multiplier stages and a regenerative turn-off snubber

This paper proposes a novel non-isolated high step-up converter suitable for miniaturization by high frequency design. High step-up converters with voltage multipliers are promising for high frequency design because many of them can be free from coupled inductors or transformers, which may lower the voltage gain due to the leakage inductance or may cause significant AC conduction loss in the primary winding. However, two issues can still hinder further miniaturization. One is that many multiplier stages may be needed to achieve extremely high voltage gain. The other is that high switching frequency may be restricted by severe turn-off voltage surge caused by high speed switching. The proposed converter addresses the former by applying a recently reported technique to a non-isolated boost converter. Additionally, the converter addresses the latter by proposing a simple passive regenerative turn-off snubber implementable only by two diodes and a capacitor. Experiments verified that the proposed converter achieves high voltage gain with fewer voltage multiplier stages compared to prior non-isolated high step-up converters. Additionally, the snubber successfully reduced the turn-off surge into half approximately without apparent deterioration of the efficiency.