A novel adaptive state-of-charge balancing control scheme for cascaded H-bridge multilevel converter based battery storage systems

Fatih Eroğlu; Mehmet Kurtoğlu; Ahmet Eren; Ahmet Mete Vural

doi:10.1016/j.isatra.2022.09.044

A novel adaptive state-of-charge balancing control scheme for cascaded H-bridge multilevel converter based battery storage systems

ISA Trans. 2023 Apr:135:339-354. doi: 10.1016/j.isatra.2022.09.044. Epub 2022 Oct 10.

Authors

Fatih Eroğlu¹, Mehmet Kurtoğlu², Ahmet Eren³, Ahmet Mete Vural³

Affiliations

¹ Electrical and Electronics Engineering Department, Gaziantep University, 27310 Sehitkamil, Gaziantep, Turkey. Electronic address: feroglu@gantep.edu.tr.
² Electrical and Electronics Engineering Department, Gaziantep University, 27310 Sehitkamil, Gaziantep, Turkey; Electrical and Electronics Engineering Department, Iskenderun Technical University, 31200 Iskenderun, Hatay, Turkey.
³ Electrical and Electronics Engineering Department, Gaziantep University, 27310 Sehitkamil, Gaziantep, Turkey.

PMID: 36302694
DOI: 10.1016/j.isatra.2022.09.044

Abstract

Variations in state-of-charges (SOCs) of batteries in a cascaded H-bridge multilevel converter (CHB-MLC) based battery storage system (BSS) could lead to undesired efficiency and performance drops, even failure of the whole system. Hence, SOC balancing is crucial for BSSs. Avoiding over-modulation region, ensuring zero common-mode voltage and reaching balanced SOC condition as quickly as possible are the key points to consider while performing SOC balancing. In this paper, a gain-scheduling based adaptive SOC balancing method is proposed for single-phase CHB-MLC based BSSs. In the proposed method, gains of the proportional controllers are updated at each sampling time based on the mathematical relationship between instantaneous SOCs and voltage reference of the CHB-MLC. Performance of the proposed method is validated through a Monte Carlo simulation based numerical analysis and experimental studies on a single-phase three-module CHB-MLC based BSS. Results reveal that the proposed method achieves SOC balancing at least two times faster than the traditional constant gain methods while avoiding over-modulation region and having zero common-mode voltage.

Keywords: Battery storage system; Electric vehicles; Large-scale grid applications; Multilevel converters; Renewable energy sources; State-of-charge balancing.