Design Consideration for High Step-Up Nonisolated Multicellular dc-dc Converter for PV Micro Converters

High step-up nonisolated multicellular dc-dc converter has been newly proposed for PV microconverters. The multicellular converter consists of the nonisolated step-up cell converters using bidirectional semiconductor switches, and these cell converters are connected in Input Parallel Output Series (IPOS). The voltage transformation ratio of the step-up converter is in case all the transistors in cell converters are operated at the duty ratio of . The proposed multicellular dc-dc converter also accomplishes high efficiency because of no magnetic coupling such as the high frequency transformer and the coupled inductor. Laboratory prototype has been fabricated to show the feasibility of the proposed converter. Design consideration for the 20 V–40 V to 384 V, 240 W nonisolated multicellular dc-dc converter has been also conducted, and the potential to achieve the efficiency of 98% has been shown. The proposed multicellular converter contributes to realizing the environmentally aware data centers for future low carbon society.