Simulation-optimization For Configurations And Dynamic Pricing Of One-way Electric Carsharing Systems

Whether in developing and developed countries,with the promotion of concepts of green travel and sustainable development,in recent years,carsharing systems has successfully entered the market,and rapidly and expanded in the whole world.More and more enterprises start to pay attention to the carsharing market,and it is in the continuous exploration of many researchers and practitioners,problems,such as unbalanced vehicles distribution,insufficient fleet size and unreasonable station setting,have gradually emerged,and become more and more obvious after the whole market entered the era of electric vehicles.To solve the above problems,this paper firstly proposes an event-driven discrete-event simulation for one-way electric carsharing systems（OECS）based on O²DES framework,and describes the system with four kinds of modules,including station,node,link and vehicle.The proposed system considers the influence of traffic congestion and the number of shared vehicles on travel speed,established a nonlinear charging process considering the station capacity,charging speed and battery capacity,and realizes the simulation of shared electric vehicles（SEV）,gasoline vehicles（SGV）,and hybrid electric vehicles（SHEV）,respectively.Based on the high efficiency of the simulation system,this paper proposes a simulation-optimization framework that jointly determines station capacity,fleet size and trip pricing to maximize the net revenue of operators,and constructs a two-stage SPSA-OCBA algorithm to solve this problem with high dimension and randomness.Moreover,taking a carsharing system in Chengdu as an example and considering the real-world traffic network,vehicle and operation data,OECS and one-way gasoline vehicle sharing systems（OGCS）are optimized respectively to demonstrate the efficiency of the proposed framework.Drawing on the concept of carbon emission factor,this paper proposes a new indicator PPC（the profit generated per CO₂）to verify the advantages of OECS over OGCS from the perspectives of economy and environment:（1）Optimal OECS and OGCS maintain similar operation scale,but the former achieves higher profits;（2）Optimal OECS and OGCS have little difference in parking cost and parking space cost.But OECS can operate at a lower cost because of their energy costs;（3）The PPC of the optimal OECS is 1.3 times that of the OGCS,in other words,the optimal OECS achieves a higher degree of cleaner production.Further,this paper proposes an extended study to analyze the feasibility of shared hybrid energy vehicle（HEV）,builds a one-way hybrid electric carsharing system（OHECS）,and compares it with the optimal OECS by altering travel demands.The results show that:（1）OHECS achieves higher operating mileage and revenue due to its twin-engine system;and most of the journey（about 90%）of HEV is completed with electricity;（2）compared to EV,because of the lower CO₂ emissions generated by HEV when using electricity,OHECS can simultaneously achieve high travel,revenue and low emissions in a low travel demand environment;（3）In low OD environment,The PPC of OHECS is significantly higher than that of OECS,but when it goes beyond a potential limit,it will gradually decrease because more fossil fuels are used;on the contrary,The PPC of OECS increased steadily with the increase of travel demand.