Investigation of raw exhaust and diluted exhaust emission measurement systems with different modern plug-in hybrid electrical vehicles

The continuous trends of the more efficient use of resources and the reduction in pollution from vehicles are reflected in a wide range of modern propulsion concepts for the transportation of passengers and goods. Different regions in the world follow similar trends but with individual strategies and designs. One global approach is the implementation of the bridge technology of powertrain hybridization in passenger cars. The technology of the so-called Plug-in Hybrid Electrical Vehicle (PHEV) is widely known among consumers and a variety of designs are commercially available. The variety of combinations of internal combustion engines (ICE) with an electric motor and the associated measurement challenges has been described in a number of papers. This paper discusses the measurement accuracy for raw and diluted exhaust sampling (CVS) and PM/PN measurement during the typical numerous engine stop and start periods. The question is: can a single, optimized exhaust emission measurement system be capable of coping with the variety of hybrid vehicle concepts and test regulation requirements?