Investigation of Methods for Improved Exhaust Emissions Measurement of Plug-in Hybrid Electric Vehicles 2012-01-0884
Measurement of exhaust emissions emitted from Plug-in Hybrid Electric Vehicles (PHEV) presents numerous difficulties for conventional emissions measurement equipment. Significant measurement errors are introduced during the measurement of PHEV emissions using conventional emissions equipment, methods, and test cycles due to the combined operation of the Internal Combustion Engine (ICE) and electrical power sources. While previous work has identified possible sources of measurement errors using conventional Constant Volume Sampling (CVS) and Bag Mini-Diluter (BMD) techniques, this paper focuses on quantifying the measurement errors and offers suggestions for improvement.
In addition, new sampling strategies are offered to improve measurement accuracy of criteria emissions such as Hydrocarbons (HC), Carbon Monoxide (CO), Oxides of Nitrogen (NOx) and fuel economy. Modifications and enhancements to the conventional BMD and CVS systems are discussed as well as investigation of engine emissions based on short and long cycle battery charge time.