Modeling of Batteries and their Assemblies Taking into Account the Degradation of Parameters

Abstract

Abstract.In recent years, electric energy storage systems are considered as a key element in the technological development of vehicles, renewable energy. This article provides a brief description of modeling methods, some new approaches and the results of modeling batteries in parallelto-serial assemblies that can be used to design storage units for local power systems. A battery is a very complex physicochemical, electrochemical and electrotechnical object, the modeling of which can be carried out at various depth levels and by various methods. Battery modeling options are being considered. Presentation of the battery in the form of equivalent circuits is in good agreement with the general approach of graphical representation of electrical systems in such packages as MatLab-Simulink, Electronics Workbench and the like. Two directions of battery modeling can be distinguished, viz. modeling current battery parameters during a charge-discharge cycle and modeling the parameters of the functional state of the batteries over a long period of operation. These directions consider different characteristic time periods (hours and days in the first case and hundreds of days in the second one), differ in the parameters taken into account and are relatively independent. The latest versions of MatLab-Simulink have a built-in model with degradation of battery parameters. The built-in battery model is quite complex and when simulating the operation of more than one battery, the time period of counting increases significantly. When modeling assemblies from a large number of batteries connected in parallel-to-series, the time in the program practically stops, which indicates the impossibility of modeling large assemblies. Nevertheless, the Electronics Workbench electronics lab has shown its performance. When using the similarity criterion, Electronics Workbench has the potential to complicate the circuits, which makes it possible to analyze parallel-serial battery assemblies.

Keywords

• battery
• assembly
• model
• equivalent circuit
• charge
• discharge
• capacity
• aging
• degradation