Modelling and dimensioning of locally emission free hybrid powertrains in railway vehicles

Kurzfassung

Fuel Cell Hybrid Electric Multiple Units (FCEMU) offer a potential and ecologically conscientious alternative for regional passenger rail services, especially in comparison to the diesel-powered trains. FCEMUs, which utilize a combination of fuel cells and batteries, possess the notable benefit of emitting no local greenhouse gas (GHG) emissions into atmosphere. When combined with hydrogen derived from renewable sources, they become a emission free transportation option. The Hybridisation Tool, presented in this research, is an innovative development aimed at enhancing power allocation in FCEMU and Battery Electric Multiple Unit (BEMU) powertrains. This tool use algorithmically produced rules to efficiently allocate power between the fuel cells and batteries and dimensioning them. The objective of this study is to implement innovative energy management techniques and assess their effectiveness in enhancing powertrain efficiency, in comparison to traditional methods. The research specifically concentrates on developing techniques to improve operating strategies for FCEMU and BEMU, specifically on regional railway tracks that are on partially electrified or on fully non electrified. The focus is specifically on two Energy Management System (EMS) methodologies for FCEMU: Finite State Machine (FSM) EMS and 5-point EMS. A comparative analysis is conducted, particularly examining the differences in sizing recommendations for fuel cells and batteries, fuel and hydrogen consumption, average efficiency of fuel cell between these two EMS approaches. The study assesses the results on two regional tracks: A Coruña to Ferrol track and the Stuttgart to Aulendorf track. This analysis provides valuable insights into the different rules applied to fuel cells and batteries, offering a better understanding of the most effective sizing techniques and operational efficiencies within these specific energy management systems. The Hybridisation Tool effectively determines powertrain configurations based on the specific requirements of the use case. The result processing demonstrates the impact of these EMS techniques on the sizing of fuel cells and batteries, as well as the direct proportional relationship between fuel cell size and efficiency, and inverse relation with the fuel consumption for FCEMU. Furthermore, the implementation of basic EMS in BEMU powertrains shows, how it improves the efficiency and utilize both electrified and non-electrified sections in rail transport networks. It also ensures seamless transitions between catenary and battery operation. This research provides vital insights into the advancement and fine-tuning of FCEMUs and BEMUs, promoting their utilization in various rail service scenarios.