Research On Fast Charging Station Placement And Charging Scheduling Strategy Of Electric Vehicle

Due to the world's shortage of fossil fuels,new energy technologies such as wind power and photovoltaics have been rapidly developed.The continuous revolution of energy storage technology has made Electric Vehicles(EV)a hot spot in the transportation industry.Electric vehicles can not only alleviate our demand on fossil energy but also improve the living environment.It is an inevitable choice for transportation in the future.Because of the insufficient number of charging facilities and unprofessional charging scheduling,the irrational use of charging resources has suppressed penetration rate of electric vehicles.This research focuses on EV station placement and charging scheduling.Firstly,this research investigates the Fast Charging Station(FCS)placement problem,especially with the elastic demand.We propose the distance preference and waiting time preference to capture the elastic EV charging demand.and then we provide a fixed-point equation to illustrate the relationship between serving demand rate and waiting time at station.We further formulate the problem of FCS placement with elastic demand as a bi-level optimization problem.In the upper level,we design a heuristic algorithm to determine the optimal location of charging stations,with the goal of maximizing overall system profit.In the lower level,we utilize the queueing theory to analyze the optimal capacity of each charging station.We also give the sufficient condition for the existence of optimal station capacity.Simulation results demonstrate the effectiveness of our approach in improving system profit and reducing demand loss rate.Secondly,the charging strategy of EV is studied,and the load balancing mechanism based on Lyapunov is designed.EV have the characteristics of mobility and dispersion,which bring about the uncertainty of time and place of connection between electric vehicles and the grid.This uncertainty will make it uncontrollable for the queue length and system profit in the charging station.We propose the objective function of system profit maximization.Then We propose the scheduling strategy which includes dynamic pricing and charging request dispatching,task serving and dropping.Among charging stations,the dynamic pricing is implemented on marginal utility,encouraging workload migration and user demand shaping.For each station,we develop a priority-based online scheduling policy to achieve time-aware load balancing,where job urgency is characterized as dynamic priority-weight.In addition,this article also combines the users' deadline to improve their satisfaction.we theoretically prove that our mechanism can guarantee bounded queueing delay and profit optimality among users.Simulations corroborate the theoretical analysis,demonstrating the effectiveness of our mechanism.