| The electric car-sharing service is one of the green travel services,which combines the idea of "sharing economy" with the advantages of electric vehicles(EVs).It is of great significance in alleviating the problem of residents' travel,reducing the use of private cars and promoting the popularization of EVs.However,this service is still in its infancy,and the problem of vehicles' electric energy replenishment limits its development.Therefore,it is necessary to study the layout theory and method of charging and battery swapping facilities for the electric car-sharing system based on analyzing the development of electric car-sharing and the ways of vehicles' electric energy replenishment as well as vehicles' operating characteristics.Firstly,to clear and definite the research focus of this thesis,the researches of electric car-sharing,big data for the studies of EVs,charging facility layout of EVs and battery swapping facility layout of EVs are summarized to analyze limitations of current researches.After that,the development of electric car-sharing and the ways of vehicles' electric energy replenishment are analyzed.Then,vehicles' GPS trajectory data in Beijing is used to analyze their operating characteristics.Finally,two problems are solved,including charging facility layout of rental stations under the charging mode and the layout of station-to-point battery swapping facility under the battery swapping mode.Specifically,the main research contents and results of this thesis are as follows:(1)Analysis of the development of electric car-sharing and the ways of vehicles' electric energy replenishment.The development of electric car-sharing in China and appropriate ways of vehicles' electric energy replenishment are analyzed.Results show that one-way station-based electric car-sharing is the most popular in China.Charging in rental stations and station-to-point battery swapping are appropriate ways for shared EVs to replenish electric energy in the electric car-sharing system.(2)Analysis of vehicles' operating characteristics.Vehicles' GPS trajectory data in Beijing is used to identify trips as well as parking and charging events.Based on these,several indicators are used to characterize the trip,parking and charging patterns from both statistical and spatiotemporal perspectives.Results show that vehicles' charging patterns are greatly influenced by their trip and parking patterns,so the thorough research on shared EVs' trip and parking patterns is helpful to assess the spatiotemporal distribution of charging and battery swapping demands for electric car-sharing,and further provide the basis for the charging and battery swapping facility layout.(3)Charging facility layout of rental stations under the charging mode.The threestep method of charging facility layout is proposed.The first step is to identify rental stations based on the DBSCAN clustering algorithm.The second step is to describe the service ability of 4 different queuing charging systems based on the queueing theory of loss and waiting systems.The third step is to distribute chargers in each rental station based on the optimization model and the genetic algorithm.Taking vehicles' parking event data as input to distribute slow and fast chargers and run a sensitivity analysis.Results show that RSE is better in describing the reliability of charging systems' service ability and the rationality of the charger distribution between 2 optimization objectives.Meanwhile,the service ability of the waiting queueing charging system with fast chargers is the best among 4 different queuing charging systems.Under historical operational patterns,a total of 200 fast chargers distributed in 186 rental stations can provide the charging service for 98.4% of vehicles with charging demands and satisfy 89.5% of the total electricity demand,while a total of 200 slow chargers distributed in 186 rental stations can only provide the charging service for 89.3% of vehicles with charging demands and satisfy 59.8% of the total electricity demand.(4)The layout of station-to-point battery swapping facility under the battery swapping mode.The extraction process of battery swapping demands and the two-stage layout method of battery swapping facility are proposed.Stage one is to allocate battery swapping stations(BSSs)based on the set covering model.Stage two is to calculate the number of battery swapping vehicles(BSVs)and batteries for BSSs based on the timevarying optimization model.To solve these two models,the greedy algorithm and the genetic algorithm are designed.Taking vehicles' trip data as input to extract battery swapping demands,distribute battery swapping facilities and run a sensitivity analysis.Results show that when BSSs' maximum service radius is 15 km and BSVs' endurance mileage is 200 km,there are 28 BSSs with 33 BSVs and 165 batteries satisfying battery swapping demands which are derived from 629 shared EVs in Beijing under historical operational patterns.Moreover,by increasing the maximum service radius of BSSs,the scale of BSSs,BSVs and batteries can be downsized,while only the scale of BSVs can be downsized by increasing BSVs' endurance mileage. |
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