Study On Charging Strategy And Charging Station Planning Of EV Based On Spatial-temporal Characteristics

Due to the fact that fossil consumption and greenhouse gas emissions of traditional vehicles have become the main factors of energy shortage and environmental pollution,as an effective solution to this problem,electric vehicles(EVs)are becoming a new di-rection for the development of motor vehicle manufactures.Properly siting and sizing of charging stations,which is a auxiliary facility of EVs,is a key step for establishing of EV ecosystem.However,large-scale popularization of EVs in the future will have a significant impact on the operation of power grid.To mitigate the negative impact caused by EV charging load,it is extremely necessary to design a proper charging con-trol strategy to guide the charging behavior of EV users,In view of these two problems,the main work of this thesis can be concluded as follows:Design of charging control strategy for EVs:a)Considering the spatial-temporal characteristics of electric vehicles,the trip chain of EVs is decoupled and reconstructed based on NHTS dataset,then the spatial-temporal model of electric vehicles trip chain is established.b)Based on the spatial-temporal model of EVs,the dispatchable charg-ing interval of different EV users is investigated.Then a Mamdani fuzzy controller is designed to simulate the charging decision of the EV users.Finally,combining with the charging characteristics of the EV battery,the charging power function of the EVs is constructed.c).The impact of charging load on power grid is analyzed.An optimization model aiming at peak load shifting is established after selecting a proper optimization objective.The multiple population genetic algorithm(MPGA)is introduced to solve this model and the proper charging start time of different users is obtained,which goal of charging load scheduling.Siting and sizing of charging station:a)The social cost of charging station planning can be calculated by the life cycle cost theory,where the related cost of charging station is divided into three parts according to the undertakers:institutional cost,user cost and line loss cost.b)The optimal location of EV charging station with the lowest cost can be obtained by introducing the Voronoi diagram and K-means clustering algorithm to divide the service scope of each charging station in target area.c)Based on the charging mode and charging demand of EV users,the optimal capacity of charging station can be calculated by M/M/n waiting queuing model under the constrains of average waiting time of EV users.Simulation results verified the effectiveness of the designed charging control s-trategy and planning scheme of charging station?The results show that the designed charging control strategy can not only realize the peak-load shifting of the power grid,but also assist the planning of the power grid.Besides,the designed planning scheme for charging station can help select proper position and capacity of charging station.