Well-to-wheel analysis and measurement of energy use and greenhouse gas and criteria emissions in a Plug-in Hybrid Vehicle: the EcoCAR 2 case study

Abstract

This paper presents a detailed well-to-wheel anal ysis of energy use, greenhouse gas and criteria emissions for a prototype Parallel-Series Plug-in Hybrid Electric Vehicle (PHEV ) developed as part of the EcoCAR 2 competition. The EcoCAR 2 team at the Ohio State University (OSU) has designed Parallel-Series Vehicle (PHEV ) capable of 67 km all-electric range, which features a lS.9-kWh lithium-ion battery pack with range extending operation in both series and parallel modes made possible by a l.S-L ethanol (ES5) engine and a 6-speed automated manual transmission. The vehicle also has two SOkW peak electric machines, one on the front axle and one on the rear axle, that enable the vehicle to have an all electric 4WD operating mode. The OSU vehicle is designed to reduce fuel consumption, with a utility factor-weighted fuel economy of 5.19 Ll100km gasoline equivalent, while meeting the EPAs Tier II Bin 5 emissions standards. Over the course of the three year competition, the Ohio State team of approximately 40 students designed, built and tested their Parallel-Series PHEV. In addition to the mechanical and electrical fabrication work, the team also developed their own control code for the engine, transmission and supervisory controllers using Software-in-the Loop (SIL) and Hardware-in-the-Loop (HIL) techniques. The EcoCAR 2 competition and the Ohio State teams participation in it were made possible through support from the U.S. Department of Energy, General Motors, The Ohio State University, and numerous competition and local sponsors.The analysis presented in this paper is based on road data collected before, during and after the EcoCAR2 competition.The OSU vehicle finished in first place in the competition, demonstrating a fully functional PHEV that achieved significant improvements in fuel economy, and in greenhouse gas and criteria emissions. This paper illustrates the application of analysis methods developed by Argonne National Laboratory to evaluate well-to-wheel energy and emissions performance, and compares these methods with the current procedures in use by the U.S.Environmental Protection Agency (EPA) and by the European Union (EU) to establish fuel economy and emissions labels for production vehicles.