Anomalies detection in high voltage batteries of hybrid and electric vehicles

The thesis, developed in collaboration with GKN Automotive (Lohmar, Germany), presents the implementation of an analytical procedure designed for assessing and monitoring the behavior of high-voltage components within the driveline of electric and hybrid vehicles. The main goal is to identify potential anomalies or damage by analyzing significant parameters to improve vehicle safety and reliability. The motivation for this work originates from the need for a reliable diagnostic tool to be introduced during the development phase of prototype vehicles, where malfunctions and operational issues are more likely to occur. The process begins with the investigation of common faults in high-voltage components, such as inverters, electric machines, and battery packs, with a focus on their causes and effects. The literature review provided insight into the driving conditions that exacerbate these issues and the most used methods to detect and predict faults. The central part of the project is the implementation of a MATLAB algorithm to process sensor data from multiple driving cycles of five vehicles, with an emphasis on battery performance analysis. The analysis is divided into two sections: monitoring of the battery's parameters, such as temperature, voltage, and current, during the single driving cycle, and long-term estimation of internal resistance, efficiency, and battery pack health. The results allowed the evaluation of the battery packs' state of health, to improve and verify the Battery Management System tuning and functionality, and to create a comprehensive database of both critical and non-critical scenarios. In conclusion, while some aspects of the long-term analysis were less accurate due to data quality and sensor limitations, the overall procedure provided important information about battery health and performance. This work enabled the generation of a database for future Artificial Intelligence training and real-time monitoring, with potential improvements related to the monitoring of other high-voltage components such as electrical machines and inverters, further enhancing the safety and reliability of vehicles.