How advanced AVL simulation software supports the development of reduced models for battery digital twins

In the research component of the FreeTwinEV project, advanced electro-thermal models of battery cells and systems are being developed. In addition to being a member of the project’s Advisory Board, AVL has been supporting this research for several years by providing the FEI STU with access to simulation software, enabling us to explore and implement new modelling approaches. This contribution plays an important role in our research activities and directly supports the progress of the FreeTwinEV project. 

Recent modelling activities were led by one of the main researchers of the project, Ing. Martin Baťa, PhD., whose dissertation focused on multi-level electro-thermal modelling of lithium-ion cells. The work integrates experimental measurements with detailed CFD simulations using AVL FIRE M followed by their reduction and system-level modelling using AVL CRUISE M, and implementation into MATLAB/Simulink for real-time capable simulations. This approach represents an important step toward practical digital twin applications. 

The scientific impact of this research has been further confirmed by a joint publication between partners STU and Linz Center of Mechatronics (LCM), published in a Q1 journal: 

Martin Baťa et al. — Geometry-Resolved Electro-Thermal Modelling of Cylindrical Lithium-Ion Cells Using 3D Simulation and Thermal Network Reduction, Energies (MDPI), 2025. 

The publication presents a modelling approach developed at STU, based on high-fidelity 3D CFD simulations of cylindrical lithium-ion cells. These models are experimentally validated and subsequently reduced into 1D electro-thermal networks, enabling a significant reduction in computational complexity while preserving the key physical behaviour of the system. This approach allows the estimation of internal, non-measurable states, such as temperature distribution within the cell, and forms a basis for real-time capable digital twin models. 

Within the collaboration, this approach is complemented by an alternative modelling strategy developed by partners from LCM, based on system-level modelling directly from experimental data. While both approaches differ in methodology, their common objective is to achieve accurate and computationally efficient representations of battery behaviour. Their comparison provides valuable insight into model fidelity, robustness, and suitability for digital twin applications. Publication comparing these two approaches is already in the making, so stay tuned. 

In addition to these key research outputs, AVL software is continuously used in other ongoing research activities at FEI STU. These include CFD simulations of battery cooling systems, investigation of thermal phenomena such as thermal runaway, and the development of reduced-order models for scalable and real-time capable simulations. Selected student projects and theses also contribute to these activities, supporting further development and validation of the proposed approaches. 

We would like to thank AVL for their support through the University Partnership Program. By providing access to professional simulation tools, AVL enables us to carry out advanced modelling activities and contributes to the overall progress of the FreeTwinEV project. 

We look forward to continuing this collaboration and further advancing research in battery modelling and digital twin development. 

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