Parallel-Connected Battery Current Imbalance Dynamics. Issue 37 (2022)

• Record Type: Journal Article
• Authors: Weng, Andrew; Pannala, Sravan; Siegel, Jason B.; Stefanopoulou, Anna G.
• Is Part Of: IFAC-PapersOnLine. Volume 55:Issue 37(2022)
• Page Start: 37
• Page End: 43
• Publication Date: 2022
• Subjects: batteries -- current imbalance -- SOC imbalance -- heterogeneity -- parallel -- second-life; Automatic control -- Periodicals; 629.805
• DOI: 10.1016/j.ifacol.2022.11.158
• Languages: English
• ISSNs: 2405-8963

Abstract

Abstract: In this work, we derive analytical expressions governing state-of-charge and current imbalance dynamics for two parallel-connected batteries. The model, based on equivalent circuits and an affine open circuit voltage relation, describes the evolution of state-of-charge and current imbalance over the course of a complete charge and discharge cycle. Using this framework, we identify the conditions under which an aged battery will experience a higher current magnitude and state-of-charge deviation towards the end of a charge or discharge cycle. This work enables a quantitative understanding of how mismatches in battery capacities and resistances influence imbalance dynamics in parallel-connected battery systems, helping to pave a path forward for battery degradation modeling in heterogeneous battery systems.