Influence of driving cycles on exhaust emissions and fuel consumption of gasoline passenger car in Bangkok

The influence of different driving cycles on their exhaust emissions and fuel consumption rate of gasoline passenger car was investigated in Bangkok based on the actual measurements obtained from a test vehicle driving on a standard chassis dynamometer. A newly established Bangkok driving cycle （BDC） and the European driving cycle （EDC） which is presently adopted as the legislative cycle for testing automobiles registered in Thailand were used. The newly developed BDC is constructed using the driving characteristic data obtained from the real on-road driving tests along selected traffic routes. A method for selecting appropriate road routes for real driving tests is also introduced. Variations of keyed driving parameters of BDC with different driving cycles were discussed. The results showed that the HC and CO emission factors of BDC are almost two and four times greater than those of EDC, respectively. Although the difference in the NOx emission factor is small, the value from BDC is still greater than that of EDC by 10%. Under BDC, the test vehicle consumes fuel about 25% more than it does under EDC. All these differences are mainly attributed to the greater proportion of idle periods and higher fluctuations of vehicle speed in the BDC cycle. This result indicated that the exhausted emissions and fuel consumption of vehicles obtained from tests under the legislative modal-type driving cycle （EDC） are significantly different from those actually produced under real traffic conditions especially during peak periods.

Numerical model of on-road emission rates of diesel buses in Beijing

A total of 14 in-use diesel buses were selected to conduct emission measurement using a portable emissions measurement system （PEMS） in Beijing. Their instantaneous gaseous emission rates, particular matter （PM） emission rates and driving parameters were obtained. The influences of speed, acceleration and vehicle specific power （VSP） on emissions were analyzed. Based on the relationships between these driving parameters and emissions, 24 driving bins defined by speed, ac- celeration and VSP were constructed with cluster analysis to group emission rates for Euro Ⅲ and IV buses, respectively. Then the emissions reductions from Euro Ⅲ to Euro Ⅳ diesel buses were ana- lyzed. Lastly, on-road hot-stabilized emission rate model for diesel buses in Beijing was developed. Through the comparison of the model simulation emission rates with the measured emission rates, the modeled emission results were in good agreement with the measured emission results. In most of the cases, the differences were less than 12 %.

Driving pattern analysis of Nordic region based on National Travel Surveys for electric vehicle integration

Electic vehicles(EVs)show great potential to cope with the intermittency of renewable energy sources(RES)and provide demand side flexibility required by the smart grid.Furthermore,EVs will increase the electricity consumption.Large scale integration of EVs will probably have substantial impacts on power systems.This paper presents a methodology to transform driving behavior of person into one of the cars in order to analyze the driving pattern of EVs based on the National Travel Surveys.In the proposed methodology,a statistical process is used to obtain the driving behavior of cars by grouping the survey respondents according to the driving license number and car number,and mapping the households with similar characteristics.The proposed methodology was used to carry out the driving pattern analysis in the Nordic region.The detailed driving requirements and charging/discharging availability of vehicles along the day were obtained.Two types of EV availabilities were studied in this paper considering different charging/discharging conditions of EVs for the power system integration,i.e.EV availability all day and EV availability at home.The results show that the daily driving requirements of the Nordic region are not very intensive.The driving patterns of vehicles in the Nordic region vary on weekdays and weekends.The two types of EV availabilities are quite different from each other.