Multimode Operation of Resonant and Hybrid Switched-Capacitor Topologies

• Published in: IEEE transactions on power electronics Vol. 33; no. 12; pp. 10512 - 10523
• Main Authors: Schaef, Christopher, Rentmeister, Jan, Stauth, Jason T.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitors; Converters; DC-DC converter; Density measurement; Electric potential; Energy conversion efficiency; flying-capacitor multilevel (FCML); hybrid switched capacitor; Inductors; Power efficiency; Power system measurements; resonant switched capacitor (ReSC); soft-charging; Switches; Switching frequency; Topology; voltage balancing
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2018.2806927

This paper presents an overview of resonant and hybrid switched-capacitor converters with a particular focus on multimode operation. The multimode approach is discussed as a tool to affect high efficiency and power density across a wide load range, provide variable regulation, and, as a general framework, to conceptualize the advantages and opportunities of the approach compared to more traditional dc-dc converters. A general analysis is provided to quantify the advantage of hybrid and resonant converters that factors in the tradeoffs between size and loss in the magnetic component and voltage stress on the active devices. A broader set of operating modes is presented that spans continuous and discontinuous conduction and includes resonant, quasi-resonant, and more traditional buck- or boost-like operation. A prototype flying-capacitor multilevel converter is presented to demonstrate the variety of operating modes and motivate important considerations such as voltage balance on the flying capacitors.