The Modelling of Vehicle Dynamics, Performance and Energy Consumption Using Alternative Fuel Concepts
Alternative fuel concepts: soon to become part of everyday life in rail transport
Although the publicly announced intention is to further increase the share of electrified railway infrastructure, for reasons of economic efficiency and very long planning and construction periods, no short-term substitution of environmentally outdated diesel transports can be expected. Supplementary technical solutions are required: alternative fuel concepts.
These railway vehicles - often referred to as BEMU (Battery Electric Multiple Unit) or HEMU (Hydrogen Electric Multiple Unit) - will soon find increasingly widespread use:
Energy and performance aspects of traction with fuel cells or battery electrics
Vehicle-specific performance data and the tractive effort/speed diagram based on it are the foundation of computer-aided travel time calculations. In the case of classic traction concepts, the motors generally have their full traction power available for acceleration when needed.
Rail vehicles with fuel cell propulsion and those that not only have traction batteries but also allow catenary operation are considered as hybrid vehicles: The energy required for the (nominal) power of traction motors is obtained, partly in parallel, from different sources, e.g.:
- Fuel cell and battery (HEMU)
- Overhead wire and battery (BEMU in overhead wire mode)
Effects on computer-aided timetable construction
For vehicles with alternative fuels, energy calculations and balance considerations are a necessary part of the run time calculation and thus of the timetable design, provided that they are executed realistically.
In the case of hybrid or alternative fuel systems, factors such as line resistance and train path characteristics (e.g. planned stop times, running time surcharges) are much more decisive than in the case of classic types of traction as to whether a specific traction unit would be suitable at all for providing a defined operating performance, i.e. to what extent it is "drivable" with the desired rolling stock.
The tractive force/speed diagram with individual power hyperbola usually used for calculations is no longer sufficient to capture the effects mentioned.
Alternative fuel concepts within FBS energy calculation module
With the energy calculation module integrated in FBS (available for FBS users soon), journey time aspects, power balances and energy curves can be evaluated when using alternative fuel traction technologies.
Scenario 1 - Battery Railcar on Scheduled Run:
You can find more scenarios in our info brochure.
The content shown on this website reflects only a small part of the possibilities and aspects when considering alternative fuel concepts with FBS. For further explanations and more detailed information, you can download our info brochure.
In addition to the evaluation for alternative traction systems, FBS enables you to calculate the energy consumption of conventional railway vehicles. You can find more information here.
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