Impact of road gradient on energy consumption of electric vehicles

• Published in: Transportation research. Part D, Transport and environment Transport and environment, 2017-07, Vol.54, p.74-81
• Main Authors: Liu, Kai, Yamamoto, Toshiyuki, Morikawa, Takayuki
• Format: Article
• Language: English
• Subjects: Electric vehicle; Energy efficiency; Fixed effect model; Road gradient
• ISSN: 1361-9209; 1879-2340
• DOI: 10.1016/j.trd.2017.05.005

•We present the impact of road gradient on the electricity consumption of electric vehicles (EVs).•The digital elevation map data are employed for calculating the road gradient of each segment.•Fixed effects in driving patterns among various EV drivers' contribute to about 2% of model fitness.•Considering gradient impacts improve the estimation accuracy of electricity consumption from 5% to 8%.•The energy efficiency from regenerative braking systems during downward gradient road is quantified. We investigate the impact of road gradient on the electricity consumption of electric vehicles (EVs) by combining long-term GPS tracking data with digital elevation map (DEM) data for roads in Aichi prefecture, Japan. Eight regression models are constructed and analysed to compare the differences between linear and logarithmic forms of trip energy consumption, differences between considering the road gradient or not, and differences between considering the fixed effects of EVs or not. By categorizing gradients and assigning a percentage of the trip distance to each category, a significantly better model of electricity consumption can be achieved. The results of this study are a novel contribution toward understanding the challenges and benefits associated with downgrade braking on energy regeneration.