Master thesis
Title
Effects of trip characteristics in real world driving on carbon dioxide and regulated exhaust emissions for
plug-in hybrid electric vehicles.
Background
The emissions of CO2 and the regulated exhaust emissions such as HC and NOx for cars depend on the
driveline technology and the type of driving. For vehicle certification and CO2 regulation, the emissions
are evaluated on specified test drive cycles, today in the EU on the NEDC test drive cycle.
For new technologies such as plug-in hybrid electric vehicles (PHEV), which can be propelled first by
electricity and then for longer trips also by a conventional engine, the test drive cycle may be less
representative and the gains in emission decreases may possibly be underestimated. This can for instance
be due to effects of cold starts frequency. A cold start of the engine increases the specific fuel use and CO2
emissions and contributes to a large share of the regulated emissions. If the PHEV in real world driving
starts with propelling the vehicle on electricity only and the trips and distances between charging are
short, the engine will be started less frequently. Short trips tend to be conducted in lower average speed
and are more often driven in urban areas. It could thus be so that the PHEV could alleviate a higher share
of emissions in densely populated areas, where the problems of emissions are bigger.
Aim
The aim of the thesis work is to evaluate the effects of trip characteristics in real world driving in Sweden
on the emissions for PHEVs. A comparison will be done to conventional vehicles and in comparison to
different test drive cycles. The work will utilize a comprehensive database for private vehicle driving
characteristics in Sweden derived by GPS logging (Karlsson 2013). The work is part of a cooperation with
Centre for Transport Studies at KTH, Stockholm.
Prerequisites
The work is performed by 2 students. Experience of Matlab is preferable.
Contact
Sten Karlsson
Division of Physical resource theory
sten.karlsson@chalmers.se
031-772 3149
mobile 0737-553398
References
Karlsson, S. 2013. The Swedish car movement data project. PRT report 2013:1, Rev1. Physical Resource
Theory, Chalmers Univ. of Technology, Göteborg, Sweden.