PHEV Modeling:
Component Technologies Impact on Fuel Efficiency

One of the main objectives of the U.S. Department of Energy's (DOE's) Plug-in Hybrid Electric Vehicle (PHEV) R&D Plan (2.2Mb pdf) is to "determine component development requirements" through simulation analysis.

Overall fuel efficiency is affected by component technologies from a component sizing and efficiency aspect. To properly define component requirements, several technologies for each of the main components (energy storage, engine and electric machines) are being compared at Argonne using PSAT.

Per the R&D plan, several Li-ion battery materials are being modeled to evaluate their impacts on fuel efficiency and vehicle mass. Different Power to Energy ratios are being considered to understand the relative impact of power and energy.

Source: U.S. DOE PHEV R&D Plan

Several engine technology options are also being considered. Argonne is studying the impact of using a simpler, cheaper engine (rather than a state-of-the-art engine) on fuel economy. The effect of different fuels (gasoline, diesel, E85, hydrogen) on fuel economy is also being assessed using the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model.

Working in collaboration with Oak Ridge National Laboratory, electric machine design options (e.g., different base speed or technologies) are also being considered.

In additon, the impact of lightweight materials on fuel economy and demands on the vehicle powertrain and ancillary systems are being assessed.

May 2008