Input-Parallel-Output-Series Two-Stage Interleaved DC-DC Converter Using Coupled Inductors

Abstract

This paper proposes a new high step-up interleaved dc-dc converter for embedded applications with power electronics circuits. The proposed circuit consists of two boost converters and a switched-capacitor (SC) converter. To reduce the ripple current in the boost inductors, these boost converters are controlled to be in an interleaved operation. Additionally, the output terminals of the boost converters are connected in series hence the double output voltage. On the other hand, the SC converter also boosts-up the output voltage of the boost converters to obtain a higher boost ratio. The operation of the boost converters and the SC converters are cooperatively controlled through a coupled inductor. This combination of the interleaved boost converters and the switched capacitor converter allows us to achieve both a low current ripple and high step-up ratio operation. This paper explains the operational principle of the proposed circuit and its steady-state analysis. Experimental results confirm that the proposed circuit makes it possible to achieve a high boost-up ratio of 14.2 with 93.6 % power conversion efficiency.