Proposal, Analysis and Experimental Verification of Nonisolated DC-DC Converters Conceived from an Active Switched-Capacitor Commutation Cell

Abstract

This paper introduces a new family of nonisolated dc-dc converters that are generated by the integration of the active switched-capacitor (ASCC) and the conventional commutation cell (CCC). Based on the commutation cell concept, the new conceived hybrid active commutation cell (HACC) provides three different types of hybrid converters: buck, boost and buck-boost. All three converters are investigated in this study through the following approaches: topological stages, static gain analysis considering the switched capacitor features, generalization of the HACC and gain for M cells and steady-state analysis. The buck version presents a high conversion rate, which demonstrates that it has potential for step-down applications. To verify the proposed topologies, a prototype was built with the following specifications: 600 V input voltage, 150 V output voltage, 70 kHz switching frequency and 1 kW rated power. Efficiency close to 95% was obtained at 1 kW for the buck topology, which demonstrates that the proposed HACC can provide gain and high efficiency at the same time.