Design of a low production cost hybrid HMMWV

There is considerable interest within the military in improving the fuel efficiency of its vehicles. Hybrid powertrains for military applications offer the potential for improved fuel economy, enhanced stealth (silent operation) capability, and auxiliary field power generation. While recent hybrid electric HMMWV conversions have shown impressive performance, the likely estimated production cost is high. In cooperation with the National Automotive Center (part of the United States Army Tank-automotive and Armaments Command, TECOM), Oak Ridge National Laboratory (ORNL) and The University of Tennessee (UT) have conducted a conceptual design for a low production cost hybrid electric powertrain for the HMMWV. The design takes maximum advantage of commercial off-the-shelf (COTS) technology. The parallel, electric assist configuration offers hybrid performance equivalent to the conventional base vehicle for limited time periods, silent electric operation, and limp-home capability in the event of electric drive system failure. The design goals for the hybrid electric powertrain, the overall system design, and design decisions necessary to meet performance goals are reviewed. Performance simulation results show that the proposed powertrain design should meet or exceed the stated design goals.