Deutsche Bahn and mtu test train equipped with hybrid drive system

• Field trials scheduled for second half of 2011
• Underfloor drive system for DMUs with diesel engine and electric motor including exhaust gas aftertreatment
• Braking energy is used for starting and for stop-and go operations
• Up to 25 per cent fuel savings and reduced CO2 emissions

Friedrichshafen/Aschaffenburg, 22 September 2010. The Tognum subsidiary MTU Friedrichshafen GmbH and the Deutsche Bahn subsidiary DB RegioNetz Verkehrs GmbH Westfrankenbahn have signed a co-operation agreement for testing a railcar equipped with a hybrid drive system. As part of this research project, a prototype of the hybrid Powerpack developed by mtu is to be tested in a Class 642 local transport railcar on the line from Aschaffenburg to Miltenberg in the second half of 2011.
The hybrid Powerpack is an underfloor drive unit that recovers energy released during braking and uses it again for starting and for stop and go operations. In a parallel hybrid configuration, it can be driven either by the diesel engine or by the electric motor, or by a combination of both diesel and electric. This can lead to a reduction of up to 25 per cent in terms of fuel consumption and carbon dioxide emissions. The testing of the hybrid railcar will be financed by the German Ministry for Transport, Construction and Urban Development (BMVBS) as part of the Electric Mobility in Pilot Regions project, which is being co-ordinated by the NOW GmbH (National Organisation for Hydrogen and Fuel Cell Technology). Approval for the required funding amounting to a total of 1.9 million euros was handed over to the project partners yesterday by Transport Minister Ramsauer.
The operating principle of the hybrid Powerpack is based on the recovery of braking energy via the generator by means of regenerative braking. During starting and acceleration, the energy storage system transmits the previously stored energy via a DC/AC converter to the generator, which then operates as an electric motor to accelerate the railcar. Depending on the amount power required by the train driver, the railcar is driven either by the electric motor alone or by a combination of both diesel engine and electric motor. The use of this technology makes low-noise and low-emission rail operations possible in railway stations and on inner-city routes. It is particularly efficient on local public transport services with frequent braking and acceleration (stop and go), since this results in a large number of charging and discharging cycles.
The motor/generator unit was jointly developed by mtu and a system partner. The 6H 1800 R75 diesel engine has a power output of 315 kilowatts, with an output of up to 400 kilowatts in the case of the electric motor. In addition, an SCR exhaust gas aftertreatment system, complete with urea tank has been integrated into the hybrid Powerpack to meet the EU Stage III B emission standards that will come into force as from 2012. In this combination, the hybrid Powerpack is an ideal choice for environmentally-friendly repowering of existing DMUs (Diesel Multiple Units).