"In the last 12 months we have developed, or helped develop, 10 different alternative powered vehicles, either electric, range-extended, or hybrid vehicles," said Dr. Jochem Wolschendorf, Chief Technical Officer and Vice President of Vehicle and Drivetrain Engineering for FEV.
The global engineering-services company sees vehicle electrification as a key driver for its future business. It has been attracting a growing number of development programs, based on its traditional engineering expertise coupled with a significant investment in dedicated test and simulation equipment and facilities.
More than 70 engineers with experience in hybrid and electric powertrain development are supported by 16 specialized test cells for electrified powertrain development. Customers include BMW, which recently revealed FEV “significantly” contributed to its development of the hybrid version of the X6. Heavy-duty vehicle and off-road equipment customers also use the services.
For basic powertrain and subsystem development, the company offers eight hybrid powertrain dynamometer test cells, two hybrid transmission-only test cells, and four electric motor test rigs.
What makes a hybrid dynamometer special? “The hybrid cell is a conventional, transient test cell with a crucial third dimension,” explains Wolschendorf. It not only varies speed and load but also electric power.
Transmission-only and electric motor test cells are cost-effective alternatives for developing subsystems and components. Each cell connects to a high-voltage battery emulator. Using FEV’s proprietary HYSIM software, they simulate real-world test conditions. This includes specific test cycles such as FTP, US06, European NEDC, or any other, according to Wolschendorf.
The heart of FEV's system may well be the battery emulator. This simulates battery drain, charge, degradation over time, affects of ambient temperature (think desert vs. subarctic), and limitations of a particular battery chemistry. The battery emulators at FEV are sourced from AeroVironment. They consist of combinations of two different models, the ABC-150 and AV-900.
FEV wrote the communication software in addition to the battery models. Battery models are in The MathWorks MATLAB Simulink. Each cell is outfitted with sophisticated safety controls for personnel—vital for working around equipment that generates up to 900 volts. The highest power cell is capable of handling 250 kW.
As it does for conventional powertrains, FEV provides base calibration of hybrid powertrains.
“Hybrid powertrains are more involved,” explained Kevin Rzemien, Manager of Electronics and Controls. “You have to calibrate the engine, transmission, electric motor, and the battery as a complete package.”
FEV provides complete calibrations for systems, or it collaborates with customers in calibration.
Recent experience showed FEV it needs more than powertrain and subsystem test cells. “One of the bottlenecks and weak links of hybrid development is the battery,” explained Wolschendorf. When developing an entire vehicle program, if the prototype or test battery runs into development problems, there is risk to the schedule. Enter FEV's full chassis-roll dyno test cell.
“We built it after we went through some painful exercises," he explained. "We decided that with the proper facility, we could operate the vehicle without the target battery. We could continue systems and subsystem development in parallel with the battery development.”
The chassis-roll dyno is approximately one year old. It features a battery emulator connection (and related safety features) that reduces the effects of battery pack delays. Even if the battery is working well, it minimizes delays due to recharge time, speeding development of other subsystems.
Though hybrid powertrain test cells are becoming more common, a full hybrid chassis dyno is currently rare in the industry.
The other specialized cell FEV recently added is an NVH cell.
“With no engine noise to mask structure-borne and airborne noises, new levels of NVH concerns are arising,” said Wolschendorf. “An electric vehicle is supposed to be absolutely quiet, but without engine masking, you suddenly hear noises that you have never heard before. If you have ever heard an electric motor spinning and the 'whine noise' it creates, it can be quite irritating even if low in volume.”
To meet the challenges of this new technology, FEV adapted an existing NVH test cell with a battery emulator and safety systems.
To grow its expertise in electric, alternative powertrains, FEV is currently engaged in some internal developments, both in North America and Europe. It is teaming with Energy Innovation Group Ltd. (EIG), a manufacturer of lithium-ion-polymer batteries, to develop a 21-kW-h Li-ion battery pack. The pack is for a Range-Extended Electric Vehicle (ReEV) project based on a Dodge Caliber.
FEV displayed the modified Caliber at the 2009 SAE World Congress. Its European arm, FEV Motorentechnik GmbH, won the eCarTec Award last October. This winning vehicle is a plug-in electric Fiat 500. Its Range Extender Module powers a 45-kW traction motor from a 12-kW-h Li-ion battery. FEV is constructing a small production run of these vehicles for fleet testing.
“Hybrid powertrains have the potential to be a real game-changer,” explains Gary Rogers, FEV's President and Chief Executive Officer. His logic is simple: Reducing fuel consumption can solve either a country’s foreign dependence on oil or the reduction of greenhouse gases, or both.
According to Rogers, with a worldwide governmental push to trade gasoline mobility for electron mobility, vehicle electrification development is upon us.