Bi-Mode Hydrogen Train Requirements Using Geospatial Line Assessment

Kurzfassung

In this paper we analyse use-cases of bi-mode multiple units with a fuel cell hydrogen power pack to identify vehicle requirements arising from infrastructure and operation. For this, we develop a methodology combining a geospatial assessment on available open data (i.e. Open Street Map and a digital elevation model) and a longitudinal dynamic simulation model of rail vehicles. Open data railway networks are suitable in this manner, but elaborate measures to account for data gaps and data inconsistencies are needed. Therefore, we deploy a routing and a smoothing algorithm for elevation profiles integrated in a geospatial model. The modelled data is fed into a simulation tool, which simulates force and speed trajectories at wheel. From the resulting trajectories we determine the necessary traction power at wheel, which has to be subsequently covered by a traction system. From the defined power demand, we derive indicative values for a fuel cell system and resultant net usable battery capacity. We deploy our model on a collection of railway services in Spain, Portugal and Germany currently operated with diesel multiple units. We consider 23 use-cases with varying vehicles and operational configuration. Determined power rates vary strongly and are especially sensible to operational issues such as very long or very short stopping times and to vehicle parameters such as vehicle mass. We determined net power at wheel capacities to be covered by fuel cell system between 82 kW and 674 kW. In relation we determined net usable battery capacities between 90 kWh and 274 kWh. Those demands cover demands for traction energy at wheel level, excluding auxiliary loads and efficiencies.