The technical teasers at last year's SAE World Congress left a gaping hole as to the vehicle's identity, but this year's exhibit floor saw Raser Technologies and FEV, Inc. unveil the Hummer H3 range-extended electric vehicle (ReEV).
"This year we are showing the completely driveable, demonstrator vehicle. And we are pleased to announce that the vehicle has been undergoing vehicle testing on-road in addition to utilizing FEV's hybrid chassis dynamometer for the last few months to prove the concept's viability," said Joachim Wolschendorf, FEV's Chief Technology Officer and the vice president of FEV's Vehicle and Drivetrain Engineering Division.
Raser provides the demonstrator concept, on display at FEV's booth (1425), with its propulsion system. The vehicle uses Raser's 200 kW traction motor mated to a 4-speed automatic transmission. Raser's 100 kW generator-driven by a 2.0-L SIDI turbocharged GM Ecotec 4-cylinder engine-provides the electrical power. The H3 demonstrator concept is the first vehicle equipped with Raser's scaleable plug-in series hybrid-electric technology.
Hummer is perceived as one of the worst offenders in terms of fuel economy and emissions, said Kraig Higginson, Chairman of Raser Technologies in Provo, Utah. Raser's enhancements have helped green the H3. "This vehicle will run with no gasoline for 40 miles, and after 40 miles the combustion engine turns on and runs at its most efficient point just to charge the battery, and then [the engine] shuts off," he said.
The transformation of a production Hummer H3 to a ReEV has the attention of General Motors' engineers. "Our engineering guys are looking at everything every time there's a product announcement, so they'll look at (the ReEV H3) to see what FEV and Raser came up with. We had some investment with this from a product standpoint, so our engineering guys have been kind of watching it from afar until it got to this point. It was literally driveable only a couple of weeks ago," said Jim Taylor, Hummer CEO.
The production Hummer H3 is available with either a 3.7-L inline 5-cylinder or 5.3-L V8 engine, neither of which was retained for the H3 ReEV. "We kept the production transmission, but mated it to the electric traction motor. Due to the electric drive requirements, we had to convert all accessory drive components—heating, A/C compressor, power steering pump, etc.—to electrically driven units for engine-off operation," noted Wolschendorf.
Vehicle development work continues. "The battery is the component [that] still requires the most development effort. FEV was significantly more involved in the battery development and the battery management than originally anticipated," explained Wolschendorf, adding, "Our hybrid experience and battery emulation capabilities provided an alternative to continue development as we assisted in the battery-pack development."
FEV handled full vehicle integration, including electrical and mechanical design, and FEV developed all software for the hybrid control unit and in-vehicle graphical display. "The most challenging and enjoyable task was the refinement of the entire control strategy, including operating modes and overall strategy," Wolschendorf said.
The driveable H3 ReEV represents a good step for the Hummer brand. "The future state of Hummer would definitely benefit from alternative propulsions. Is that natural gas? Is that electric? Is that two-mode?" Taylor asked and answered by saying, "For the future of Hummer we need to incorporate one of those alternative propulsion solutions."
Raser and FEV's demonstrator H3 ReEV is just the start of something more. "This is only one vehicle, but there are other vehicles in process," said Higginson, adding, "We're looking at various powerplants to drive this vehicle that are even more efficient and use E85 fuel. We're continually working."