The Research On Rapid And Coordinated Charging Strategy For Private Electric Vehicles

With the development of modern society and economy,the development trend of the automobile industry will inevitably be the electric vehicle industry in the future.Compared with traditional fuel vehicles,the development of electric vehicles can reduce the greenhouse effect caused by carbon dioxide emissions from automobile exhaust,reduce the destruction of the greenhouse effect on the environment and climate;on the other hand,it can also reduce the human dependence on traditional fossil energy.We can use clean energy to replace traditional fossil fuels and actively respond to the country's call for the development of clean energy.Although electric vehicles have many advantages,electric vehicles are powered by vehicular batteries and can be charged to electric vehicles by charging piles.If the large-scale electric vehicle as a charging load access to the distribution network in disorderly manner,it will inevitably bring a series of negative impact on the safe and stable operation of the power grid.In order to ensure the stable and safe operation of the power grid,so it is necessary to conduct a rapid and coordinated charging study on electric vehicles.First of all,this paper analyzes the influencing factors of the charging load modeling of electric vehicle charging stations and the current research status of the EV charging strategies at home and abroad.Aiming at the problem of rapid charging of electric vehicles,the factors such as the peak filling and filling,the position information of the charging station and the individual charging preferences of the electric vehicle users are taken into consideration,so that they are all considered in the process of orderly charging of electric vehicles to develop orderly charging strategy of private electric vehicles.The formulation of an orderly charging strategy first considers the user's personal charging preferences(time to reach the charging station,waiting time for queuing,charging start time,charging end time,etc.)and the road traffic network model.Assuming that the initial position of the electric vehicle is at a random point,The Floyd algorithm is used to calculate the shortest distance from each initial point to the charging station and a charging model for the charging station is established.Secondly,two rapid coordinated charging strategies are proposed.One is to establish a coordinated charging strategy to minimize the total charging time,minimum power standard deviation and peak valley difference of the distribution network.And the weighted summation method is used to normalize the multi-objective function into a single target solution.The other is that the total charging time of the electric vehicle is used as the constraint condition to achieve the peak-to-peak distribution of the distribution network the total charging time of the electric vehicle is used as the constraint condition to realize the peak filling of the distribution network.The genetic algorithm is used to solve the problem of optimal charging strategies of electric vehicles.Finally,taking the traffic network data of Lanzhou working day and holiday as an example,the simulation and analysis of two order optimization schemes under working day and holiday are carried out respectively.The simulation results show that: when disordered charging,the total charge time is the least,and the effect of peak filling and valley filling of distribution network is the worst.In the orderly charging strategy of the electric vehicle that does not consider the time of objective function,the peak-cutting and valley-filling effect of the distribution network is the best,and the total charging time is the longest;When the orderly charging strategy of electric vehicles considers the time objective function,the peak-shaving and valley-filling effect of the distribution network is in the middle.