Model Order Reduction zur gezielten Analyse von Einflussparametern auf den Thermal Runaway und seine Propagation
In its new climate plan "Fit for 55", the EU Commission calls for carbon dioxide emissions to be reduced by at least 55 percent by 2030 compared to 1990. Cost reduction, range increase, and fast charging capability, all at the highest safety level, are necessary to further improve the acceptance of electric vehicles and thus the share of electromobility.
The range increase in particular leads to an increased risk of thermal runaway (TR) and thermal runaway propagation (TR-P) in the battery pack, as it is accompanied by an increase in the energy density of the cells and the overall battery. Due to the constant increase in the energy densities of the cells, safety must also be re-evaluated with each new cell generation and each new battery design. This constant re-evaluation of the safety of battery electric vehicles poses major time and cost problems for vehicle manufacturers, system suppliers and subcontractors.
Current high-fidelity simulation models are not applicable for a comprehensive analysis of influencing factors on TR-P, despite modern computer infrastructure and due to the long computing times in the development process of battery systems.
The main goal of MORE+ is the realisation of extensive influence parameter studies at pack level. This will enable even better and novel innovative TR-P safety concepts to be developed. For this purpose, a reduced combined multi-physical battery model is built with appropriate coupling from the individual models to be reduced, TR, crash, thermal management and normal operation.
The following sub-objectives are derived from this:
- Develop a methodology to optimise battery packs with respect to the prevention of TR and TR-P using a reduced combined multi-physical battery model
- To derive important findings for a potential early detection of TR and TR-P from a Fibre Bragg measurement (temperature and forces) for the error case
- Innovative test methods for the fault case provide important insights for the model design and serve as a basis for possible test guidelines for safety tests and calibration tests
The MORE+ project provides an important gain in knowledge regarding influencing parameters on the TR-P, which is not yet possible with the current models. The reduced models offer great potential for reducing development time and costs in the future. A Thermal Runaway (TR) test with a prototype battery causes costs in the amount of about 100 000 € (implementation 45 000 € and prototype battery 55 000 €) and a small new safety precaution, such as additional insulation foil about 90 000 € for a quantity of 100 000. There is great potential for savings here by substituting physical tests with simulation and an effective evaluation method.
With the possibility to carry out extensive influence analyses also in the development process, the holistic consideration of safety concepts in the virtual development process is significantly expanded and strengthened. MORE+ thus contributes to even safer electromobility in the future that is accepted by society.
