S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Civil & Environmental Engineering (건설환경공학부) Theses (Master's Degree_건설환경공학부)
A Dynamic User Equilibrium Model of Battery Electric Vehicles Considering En-route Recharging Behaviors
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- 공과대학 건설환경공학부
- Issue Date
- 서울대학교 대학원
- Dynamic User Equilibrium; Dynamic Traffic Assignment; Battery Electric Vehicle; Range anxiety
- 학위논문 (석사)-- 서울대학교 대학원 : 건설환경공학부, 2017. 2. 고승영.
- Facing with increasing demands on Battery Electric Vehicle (BEV), public interests of incorporating BEVs into existing operational and planning models of transportation systems are growing recently. Unlike gasoline vehicles, BEV users encounter range anxiety that comes from short driving range, long charging time, and insufficient charging infrastructures. BEV drivers who encounters the range anxiety problem are expected to have different route choice behaviors from the existing drivers and will resist being stuck in the middle of trips, for not having enough battery states.
Several models have been developed to reflect this aspect in static traffic assignment models. However, Dynamic Traffic Assignment (DTA) incorporating BEVs on it have hardly been researched yet. In addition to generally researched static models, the temporal approach toward BEV can broaden analytical scopes in a temporal manner and can be used for analysis related to operational planning. Therefore, this research proposes a Dynamic User Equilibrium (DUE) model of BEVs that can reflect drivers behaviors incurred by range anxiety.
In this research, a trip-based DTA model for BEVs is developed. It is because the usable paths of a BEV are completely determined by its remaining battery state, a path-based discrete time DTA model is formulated to track the battery states of BEVs at each time interval. The models objective function is composed of travel time and out-of-range penalty term induced from battery shortage for assigned path flows. A modified iterative flow swapping algorithm is adopted to gradually decrease the out-of-range penalty and travel time gap between shortest paths and non-shortest paths.
The suggested model is applied to an example problem of Nguyen-Dupuis network with insufficient initial battery state. As a result, given with insufficient initial battery state, traffic flows of BEV detoured to maintain their batteries to be higher than minimal comfortable amount in a dynamic transportation system.
The experienced travel time for traffic flows that had the same O-D and departing time interval showed identical value and traversed their paths without running out of batteries.