48 V to 1 V DC-DC Converter Based on Cascade/Ladder Connected Switched Capacitor Cells

Neilor C. Dal Pont; Jessika M. de Andrade; Chokkalingam Bharatiraja; Brad Lehman; Telles B. Lazzarin

doi:10.18618/REP.e202525

Authors

Neilor C. Dal Pont Universidade Federal de Santa Catarina https://orcid.org/0000-0003-1381-7485
Jessika M. de Andrade Universidade Federal de Santa Catarina https://orcid.org/0000-0003-2974-5711
Chokkalingam Bharatiraja SRM Institute of Science and Technology https://orcid.org/0000-0003-2517-2119
Brad Lehman Northeastern University https://orcid.org/0000-0003-1120-399X
Telles B. Lazzarin Universidade Federal de Santa Catarina https://orcid.org/0000-0001-8598-8641

DOI:

https://doi.org/10.18618/REP.e202525

Keywords:

Non-Isolated DC-DC Converters, Step-down converter, Switched-capacitor cell

Abstract

This paper proposes a cascade/ladder switched capacitor converter integrated with an interleaved synchronous buck converter to provide a 48 V to 1 V conversion for data center applications. The switched capacitor stage decreases the input voltage from 48 V to 3 V (a reduction of 16 times), with low voltage stress on the input switches and intermediate voltage levels that can be used as voltage sources. The interleaved buck stage provides voltage and current control and is connected in cascade with the switched capacitor stage to reduce the voltage from 3 V to 1 V (a reduction of 3 times). Furthermore, a switching frequency optimization is proposed for the switched-capacitor converter to maximize efficiency. The proposed solution was experimentally validated in a two-stage 30 W prototype: the first stage is the proposed cascade/ladder switched capacitor topology (48 V to 3 V) with unregulated conversion, which provides a maximum efficiency of 91,6%, and the second stage is the buck converters (3 V to 1 V) with regulated conversion.

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Author Biographies

Neilor C. Dal Pont, Universidade Federal de Santa Catarina

was born in Criciúma, Santa Catarina, Brazil, in 1989. He received his B.Sc., M.Sc., and Ph.D. degrees in Electrical Engineering in 2015, 2017, and 2022, respectively, from the Federal University of Santa Catarina (UFSC), Florianópolis, where he was affiliated with the Department of Electrical and Electronic Engineering and the Power Electronics Institute. He is currently an electrical engineer at UFSC. His research interests focus on switched-capacitor converters, inverters, high-gain step-up and step-down DC-DC converters, resonant converters, and grid-connected systems.

Jessika M. de Andrade, Universidade Federal de Santa Catarina

was born in Florianopolis, Brazil, in July 1994, graduated in Electronic Systems at the Federal Institute of Santa Catarina (IFSC), Florianopolis, in 2015. She received a M.Sc and Ph.D degrees in Electrical Engineering from the Federal University of Santa Catarina (UFSC), Florianopolis, in 2018 and 2022, respectively. She is currently a Professor with the Department of Mobility Engineering (EMB) at the UFSC and a member of Brazilian society of power electronics (SOBRAEP). Her interests include high gain dc-dc converters, modeling and control applied to power electronics, converters/inverters with gain cells, renewable energy and related areas.

Chokkalingam Bharatiraja, SRM Institute of Science and Technology

(Senior Member, IEEE) received the bachelor’s degree in electrical and electronics engineering from the Kumarguru College of Technology, Bharathiyar University, India, in 2002, the M.Eng. degree in power electronics and drives from the Government College of Technology (Anna University Coimbatore), India, in 2006, and the Ph.D. degree in electrical engineering from the SRM Institute of Science and Technology, Chennai, India, in 2015. He completed the post Centre for Energy and Electric Power, Faculty of Engineering and the Built Environment, Tshwane University of Technology, South Africa. He is currently a Postdoctoral Fellow/Visiting Research Scientist with Northeastern University, Boston, MA, USA. He is also currently working as an Associate Professor with the Department of Electrical and Electronics Engineering, SRM Institute of Science and Technology. He has authored more than 300 scientific articles. He is a member in of the IEEE Industrial Electronics, the IEEE Power Electronics, and the IEEE Power and Energy Societies. He serves as a Reviewer for more than 50 refereed journals, in particular, the IEEE.

Brad Lehman, Northeastern University

(Fellow, IEEE) is currently a Professor of electrical engineering with Northeastern University, Boston, MA, USA. He has been listed in the inaugural edition of the book The 300 Best Professors (Princeton Review, 2012). He performs research in power electronics and renewable energy. Dr. Lehman was a recipient of the 2015 IEEE (PELS) Modeling and Control Technical Achievement Award, the 2016 IEEE Standards Medallion, the 2018 IEEE Award for Achievement in Power Electronics Standards, and the 2019 IEEE PELS Harry A. Owen, Jr. Distinguished Service Award. He was the Editor-in-Chief of the IEEE Transactions on Power Electronics from 2013 to 2018. He was the President of the IEEE Power Electronics Society (PELS) from 2022 to 2023.

Telles B. Lazzarin, Universidade Federal de Santa Catarina

(S’09-M’12-SM’18) was born in Criciúma, Santa Catarina State, Brazil, in 1979. He received his B.Sc., M.Sc., and Ph.D. in Electrical Engineering from the Federal University of Santa Catarina (UFSC), Florianópolis, Brazil, in 2004, 2006, and 2010, respectively. He is currently a Professor at the Department of Electrical and Electronic Engineering (EEL) at the UFSC. In 2006, he worked with industry, including R&D activities at WEG Motor Drives & Controls, Brazil. He was a Postdoctoral Fellow at the UFSC, Florianopolis, Brazil, in 2011 and a Visiting Researcher at the Northeastern University, Boston, USA, from 20017 to 2018. He was the Associate Editor of the Brazilian Journal of Power Electronics Power from 2022 to 2023. He is the president of the Power Electronics Association (SOBRAEP), term 2023-2025, and the Electrical Engineering Postgraduate Course Coordinator at the UFSC since 2020 (terms 2020-2022 and 2023-2025). He has been an Associate Editor for the IEEE Open Journal of Power Electronics (OJ-PEL) since 2020. Dr. Lazzarin is a member of the Brazilian Power Electronics Association (SOBRAEP), Power Electronics Society (PELS), Industry Applications Society (IAS), and Industrial Electronics Society (IES). His research areas include DC-DC converters, single-phase rectifiers, on-grid and off-grid inverters, power supplies, power converters for renewable energies, electric vehicles, and battery energy storage Systems (BESS).

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