Influence of Driving Cycle Uncertainty on Electric City Bus Energy Consumption

The objective of this study was to analyze the energy consumption variations of an electric city bus caused by driving cycle uncertainty on a specific route. A novel energy consumption analysis method was developed to create a reliable energy consumption forecast for a bus route. The method is based on synthesizing new artificial driving cycles for a selected route by compiling the new cycles from segments of actual cycles measured from the route. The segment-based synthetization algorithm randomizes the bus stops at which the vehicle stops and the measured base cycle used for each segment of the route. 4000 driving cycles were synthesized for a suburban bus route in Espoo, Finland, and a validated full- electric city bus simulation model was used to run the cycles. As a result, an energy consumption distribution forecast was obtained for the route. The energy consumption distribution forecast closely resembled a normal distribution. Furthermore, the energy consumption influence of the number of stops made at bus stops during the cycle was examined. The relationship between the number of stops and the energy consumption was linear.