MAN Truck and Bus establishes Center of Competence for hybrid drives; hybrid technology to play “fundamental role” in all commercial vehicle segments
|MAN introduced the Lion’s City Hybrid at the UITP Congress at Vienna in June 2009. Its series hybrid drive saves up to 30% of fuel in city traffic.|
MAN Truck & Bus is consolidating all its R&D activities in the field of hybrid technology in a newly created Center of Competence, which at the same time is expanding. The new Center of Competence also will be the interface to co-operation partners and suppliers as well as to further experts, such as from universities.
In September 2010, MAN Truck & Bus introduced the diesel-electric series hybrid Lion’s City Hybrid, which uses up to 30% less fuel than a conventional, diesel-powered city bus. The vehicle is already in regular operation on scheduled routes in Munich, Paris, Barcelona, Milan, Vienna and other cities. Orders for a further 66 of these vehicles have been received to date; delivery is scheduled for 2011.
In the MAN Lion’s City Hybrid, a largely standard D0836 six-cylinder diesel in an EEV version rated at 191 kW/260 hp and integrating a CRTec particulate filter is coupled with a 150 kW generator, which in turn supplies electric power to two conventional electromotors. The two strapped-down asynchronous driving motors each deliver 75 kW through a summation gearbox to the standard low-floor portal axle. In this way the unsprung masses are kept low, and the electromotors are spared impact on the axle.
The energy storage system is located on the roof, and comprises 12 modules of high-power capacitors, each of 24 cells (maximum charge/discharge 200 kW, energy content approx. 0.4 kWh), that store the recuperated braking energy. The driving motors can be powered either from the diesel generator unit or the energy storage system. The Lion’s City Hybrid can pull away from a stop just by stored electric power and without generating emissions, and only activates the diesel until when it needs more power. Low levels of power, needed to supply auxiliary units or the onboard network for example, can usually be drawn from the energy storage system.
Cutting out and starting of the diesel engine is controlled by the automatic energy management. While the bus is travelling, the diesel engine, in addition to delivering the required driving power, produces power on demand for the electrical auxiliary units depending on the available charge in the energy storage system. The air conditioning compressor and power steering pump are driven electrically.
We are convinced that hybrid technology will play a fundamental role in the future of all commercial-vehicle segments, from the city bus to the long-haul truck, in the continued increase of efficiency and conservation of resources, thus smoothing the path to E-mobility. The new Center of Competence will concentrate on hybrid technology from research right up to series production in the various product segments.—Bernd Maierhofer, Director of R&D and Purchasing of MAN Truck & Bus AG
The introduction of hybrid drives for commercial vehicles is a major challenge for all manufacturers, given the commercial users’ vastly different requirements profiles, MAN notes. While regular-service buses in cities operate in a continual cycle of acceleration and deceleration, long-haul trucks run at largely constant speeds over long distances on highways.
Trucks in the construction industry require high levels of power and traction, under some circumstances also having to drive power take-offs. Distribution trucks operate with varying loads both in and between cities. MAN is currently working on a hybrid drive for this type of operation.