Design and Analysis of a Regio-Shuttle RS1 Diesel Railcar converted to Fuel Cell Hybrid Propulsion

Kurzfassung

In the context of the UIC targets to reduce CO2 emissions by 50% until 2030 the utilization of 10 to 15 year old diesel trains becomes increasingly problematic and might lead to costly repowering procedures. Hydrogen powered Fuel Cells (FC) promise zero emissions at point-of-use and low noise operation. However, FC electric trains have so far been presented only as new built concepts (Alstom iLINT, Siemens Mireo announced for 2020) but not as conversion concepts from existing diesel trains. Conversion of diesel trains which are in operation today and approach major overhaul deadlines to electric propulsion could become a vital option to extend the vehicles lifetimes and save costs against the purchase of new built trains. We develop and discuss a conversion concept of a today widely used diesel powered B’B’ railcar in Germany, the series 650 Regio-Shuttle RS1, to a hydrogen FC hybrid train. The hybrid propulsion system consists of a proton exchange membrane FC, the H2-storage system, FC cooling unit, electric drive and converter system and a battery energy storage system. For design and dimensioning purpose several non-electrified railway lines in Germany are analyzed in terms of distances, maximum velocity, gradients and daily mileage. Based on this analysis typical lines representing different geographical topologies such as mountainous and flat regions are chosen for differentiated consideration. For these lines, power and energy demand at DC link level is derived using a backwards simulation in matlab which leads to a matrix of requirements for the components. The railway lines that have been found most demanding in terms of maximum power and daily energy demand are taken as basis for the layout of drivetrain and energy storage components. The specific components’ dimensions in terms of power, energy, mass and volume are determined by optimization related to a proposed operation strategy and are selected out of characteristic Parameters of products available on the market. Subsequently, a packaging and vehicle integration concept is elaborated on the basis of these specifications. Based on the drivetrain layout and usage pattern we estimate costs of the FC hybrid drivetrain and energy storage components and calculate the trains’ CO2 emissions for different hydrogen production and delivery pathways based on a well-to-wheels approach. Finally, we discuss our results in terms of technical, operational and economic advantages and constraints.