Title: A hierarchical cascaded multilevel converter with continuous uniform SOC management for battery storage systems

Authors: Zuhair Alaas; Jianfei Chen; Caisheng Wang

Addresses: Electrical Engineering Department, College of Engineering, Jazan University, Jazan, Saudi Arabia; Department of Electrical and Computer Engineering, Wayne State University, MI, USA ' Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA; Department of Electrical and Computer Engineering, Wayne State University, MI, USA ' Department of Electrical and Computer Engineering, Wayne State University, MI, USA

Abstract: This paper presents a hierarchal cascaded multilevel converter (HCMC) for continuous uniform SOC operation of battery energy storage for a powertrain system. The proposed HCMC is a combination of half-bridge converters and H-bridge unfolders with the feature of modular design for cost reduction and reliability improvement. Furthermore, continuous uniform SOC operation can be achieved via the proposed topology without adding additional balancing circuits, which guarantees high utilisation and reliability of the batteries. Failed individual battery modules/cells can be bypassed via the converter without bringing down the whole battery system. Detailed hardware implementation is described with a double reference signal-based carrier phase-shifted modulation scheme. Both simulation and experimental results have been carried out to verify the performance of the proposed HCMC with a continuous uniform SOC control strategy.

Keywords: battery energy storage system; BESS; cascaded multilevel converter; hybrid topology; state of charge; SOC; phase-shifted modulation.

DOI: 10.1504/IJPT.2022.124750

International Journal of Powertrains, 2022 Vol.11 No.2/3, pp.160 - 180

Received: 10 Aug 2021
Accepted: 23 Dec 2021
Published online: 08 Aug 2022 *

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