Evaluation and comparison of two approaches to capture the electrical behaviour of battery cells. (August 2020)

• Record Type: Journal Article
• Authors: Ziese, Johann; Franke, Marcel; Kowal, Julia
• Is Part Of: Journal of energy storage. Volume 30(2020)
• Publication Date: 2020-08
• Subjects: Equivalent circuit model -- Mathematical model -- Shepherd equation -- Photovoltaic; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2020.101463
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: Lead-acid, lithium-iron phosphate and lithium titanate batteries can be modelled using the same model structure. Shepherd model more accurate for lead acid batteries than lithium batteries. Equivalent circuit model (ECM) depicts dynamic behaviour more accurate than Shepherd model. ECM not suitable for lead acid batteries when both charge and discharge are considered. Both models do not cover hysteresis effect properly. Abstract: This paper presents a comparison of two models to predict the electrical behaviour of a lithium titanate (LTO), a lithium iron phosphate (LFP) and a lead acid cell. One model is based on a an equivalent circuit (ECM) and the other one is based on the Shepherd equation. The models are compared by evaluating constant current charge/discharge curves and dynamic characteristics of a typical photovoltaic (PV) scenario. The results show that the lead acid cell is better modelled using a Shepherd style model due to its different charge/discharge characteristics. The lithium-ion technologies are better represented by an ECM due to only minor deviation in charge/discharge parameters. Overall the ECM is better suited for depicting the dynamic behaviour of cells while the Shepherd model is more accurate in static charge/discharge curves and where cell characteristics differentiate between charge and discharge.