High-Efficiency Multilevel Flying-Capacitor DC/DC Converter for Distributed Renewable Energy Systems

This paper presents a high-efficiency multilevel flying-capacitor (FC) dc/dc power conversion with a lower passive component rating and power device count for distributed renewable energy systems. A resonant technique is adopted for the proposed dc/dc converter to achieve zero-current switching (ZCS) for all switches. Theoretical analysis is carried out for the proposed quintuple topology with three active switches. The proposed converter is evaluated to the conventional FC converter, in terms of the component rating and count, to highlight its advantages with respect to the power density and cost. The experimental results of a 1-kW prototype FC converter are presented to validate the theoretical analysis and principles, as well as attest the feasibility of the proposed topologies.