Benchmarking battery management system algorithms - Requirements, scenarios and validation for automotive applications

Abstract

State estimators are crucial for the effective use of batteries in real-world applications. Insufficient algorithms can lead to user dissatisfaction, safety risks, and accelerated battery degradation, posing significant risks to manufacturers. Developing algorithms for battery management systems (BMS) involves defining requirements, implementing algorithms, and validating them, which is a complex process. The performance of BMS algorithms is influenced by constraints related to hardware, data storage, calibration processes during development and use, and costs. Additionally, state estimation methods vary widely, requiring specific data that impact algorithm performance.

This study investigates these complexities in the development of state estimators and underscores the importance of their performance. We established an approach for selecting test scenarios, based on expert interviews, which considers computational capabilities and specific application scenarios. A model-based simulation environment is introduced to handle the complexities of validation. This environment enables thorough validation of the algorithms under real-application conditions, different test scenarios, and parameter variations.

We exemplarily perform a validation for three State of Charge (SoC) estimators under diverse conditions and cell variations. The results show the performance dependencies on temperatures, cell chemistries, initial SoCs and measurement inaccuracies. Additionally, the cell-to-cell variations highlight the complexity and effort of algorithm validation. Introducing an additional scenario parameter expands the range of test scenarios, emphasizing the necessity to select scenarios that accurately reflect field conditions and worst-case situations.