Hybrid Architecture Selection to Reduce Emissions and Petroleum Energy Consumption

The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is participating in the 2012 - 2014 EcoCAR 2: Plugging in to the Future Advanced Vehicle Technology Competition series organized by Argonne National Lab (ANL), and sponsored by General Motors Corporation (GM), and the U.S. Department of Energy (DOE). The goals of the competition are to reduce well-to-wheel (WTW) petroleum energy consumption, WTW greenhouse gas and criteria emissions while maintaining vehicle performance, consumer acceptability and safety. Following the EcoCAR 2 Vehicle Development Process (VDP), HEVT will design, build, and refine an advanced technology vehicle over the course of the three year competition using a 2013 Chevrolet Malibu donated by GM as a base vehicle. In year 1 of the competition, HEVT has designed a powertrain to meet and exceed the goals of the competition. This paper presents a comparative analysis of three candidate powertrain architectures: a Battery Electric Vehicle (BEV), a series Extended Range Electric Vehicle (EREV) and a series-parallel switching (SPS) EREV. A design matrix is then used to select the superior architecture based on the modeling results. The design processes shows that the SPS EREV is the superior of the three candidate architectures. The selected architecture is then explored in greater detail, yielding a common set of metrics that form Vehicle Technical Specifications (VTS). The resulting VTS is compared to the VTS of the stock Malibu to quantify the modeled fuel consumption and emissions reduction of the selected hybrid architecture.