CUMMINS WORKING ON TWO PHEV PROJECTS FOR BUSES
The first project, in partnership with the Ohio State University, PACCAR, NREL and Argonne National Laboratory and funded with $4.5 million from the DOE, is to develop a Class 6 commercial plug-in hybrid electric vehicle that can reduce fuel consumption by at least 50% over conventional Class 6 vehicles.
Cummins researchers will optimize the powertrain by selecting the engine with the best architecture to use as an electric commercial vehicle range extender, using the engine to manage the charge level of the all-electric drive battery pack. The range extender will be integrated, using advanced vehicle controls, with the electrified powertrain and other applicable technologies.
The second project, in partnership with TM4, STL (Société de transport de Laval, the public transit system in the city of Laval, Québec) and IVI (Innovative Vehicle Institute, a non-profit research center), is developing two different models of a plug-in hybrid bus, using different battery chemistries and charging schemes.) The plan with this project is to let the two different chemistries - LTO and NMC - compete head to head for more than a year, and see which one wins.
LTO is a power battery, handles high C rates and has good durability. NMC has double the energy capacity and is attractive from a cost point of view, but carries risk in performance and durability. Both chemistries meet the performance targets.
One bus will be LTO, the other bus will be NMC. The buses will use an on-board 20 kW charger for off-duty charging; for an external in-route fast-charger, the team will use a 450 kW charger.
For range-extending engines, Cummins looked at the bottom half of its portfolio: engines from 2.8 liters up to the 6.7-liters. For both the DOE project and the Laval bus project, In the North American transit market, the 8.9 litre is the major engine in the space, Cummins claims it is basically cutting the displacement requirement in half with the PHEV configuration.