Modeling and Simulation of a Fuel Cell Electric Vehicle System: Analysis and Aging Estimation

With the rise of fuel cell vehicles to mass production, many technical improvements have been realized to drastically increase the range, efficiency, and sustainability of fuel cell vehicles. However, insights into those valuable state-of-the-art solutions are usually not shared with researchers due to the strict non-disclosure policies of fuel cell vehicle manufacturers. Many studies, therefore, rely on assumptions, best-guess estimates, or insider knowledge. The goal of this thesis work is to presents a comprehensive study on the development and analysis of a Simulink model for a fuel cell bus powered by hydrogen. The research focuses on two main aspects: firstly, the investigation of the electrical behavior of a battery by analyzing data released by Volkswagen for the ID.3 electric vehicle. This analysis provides valuable insights into the battery’s State of Charge (SOC), as well as various electrical parameters such as voltage, current and an estimation of the RC parameters of the battery’s equivalent electrical circuit. In addition to this, the thesis explores the State oh Health (SOH) characteristics of the battery by employing a capacity loss model. The aging study aims to understand the degradation of the high power battery over time due to various operational factors. In the second part of this work, a detailed Simulink model is presented, incorporating the fuel cell system and the previously analyzed battery and also modeling work on the performance and aging of the fuel cell was carried out. The model enables the estimation of the fuel cell bus’s performance, considering the interplay between the fuel cell and the integrated battery system. Finally, aging estimation for both the battery and the fuel cell is provided based on the specific usage patterns derived from the Simulink model. This estimation contributes to a better understanding of the long-term durability and performance of the integrated fuel cell and battery system. Overall, this thesis offers valuable insights into the electrical behavior, aging characteristics, and performance estimation of a fuel cell bus system with integrated batteries. The methodology and analysis developed in this study can be applied to various types of vehicles, including aerospace applications. By analyzing different driving cycles, this model provides an estimation of essential operating parameters and predicts the remaining life of the battery and fuel cell.