|The underfloor hybrid drive unit. Click to enlarge.|
At this year’s Innotrans rail exhibition in Berlin (23-28 September), the Tognum Group introduced under the MTU brand a prototype of a new underfloor hybrid drive system for railcars. MTU estimates that fuel consumption and carbon-dioxide emissions can be reduced by up to 25% with the hybrid drives, depending on the route.
The hybrid drive combines a MTU Series 1800 six-cylinder inline diesel with a motor/generator unit and energy storage system; electrical output of the unit is 400 kW. The generator will recover kinetic energy during braking which can be used during acceleration and in stop-and-go operation.
|The Series 1800 six-cylinder inline engine with generator. Click to enlarge.|
Depending on how much power is required by the train driver, the railcar is propelled either solely by electrical power or by a combination of diesel engine and electric motor. In railway stations or in urban areas, this allows trains to operate with low noise and low emissions. Hybrid drive is particularly economical on local transport routes with frequent braking and acceleration, because this results in many charging and discharging cycles.
The drive unit is based on the existing PowerPack 6H 1800, an underfloor diesel-powered motor/generator that delivers maximum power output of 390 kW. MTU developed the engine/generator unit jointly with a system partner.
In addition the hybrid power pack includes SCR exhaust-gas after treatment with a urea tank; this is a prototype that fulfills the emission regulations applicable to Stage IIIB non-road diesel vehicles as of 2012.
The underfloor drive modules could be used to upgrade existing diesel-powered trains as well as in new construction.