Research On Charging Demand Prediction And Charging Strategy Of Electric Vehicles Considering Spatial And Temporal Distribution Characteristics

In recent years,the world's environmental pollution and energy problems are becoming more serious.Electric vehicles are becoming more and more popular because of the advantages of environmental protection and energy saving.The promotion of electric vehicles has made obvious effects.However,the disordered access of electric vehicles to the power grid will aggravate the peak and valley difference and make the load fluctuate greatly,which is not conducive to the stability and safety of the power grid.At the same time,electric vehicle users will also pay high charge costs under this condition.Therefore,it is very necessary to study and solve this problem.First of all,the paper studies the charging load of electric vehicles in the city.Using the theory of travel chain,considering factors such as electric vehicle charging place,charging start time,mileage and charging frequency,taking a district as an example,an electric vehicle charging model considering time and space distribution in the city is established.The influence of the permeability of the electric vehicles is also analyzed.Secondly,the paper proposes an improved firefly algorithm.When the firefly algorithm is updated,an adaptive mutation operator is introduced.The operator can solve the problem that the basic firefly algorithm will easily fall into local optimum,and makes the optimization speed faster and more precise.Based on the established electric vehicle charging model,the improved firefly algorithm is applied to optimize the charging model,which achieves the goal of stabilizing load fluctuation,cutting peak and filling valley,and verifies the correctness and advancement of the optimization strategy.Then considering the factors of Time-of-use price,the charging of electric vehicles is optimized again,and the optimization effect is analyzed from a quantitative perspective,which reflects the effectiveness of the algorithm again.Finally,the paper establishes an electric vehicle charging model of freeway which considers spatial and temporal distribution,and puts forward the corresponding optimization charging strategy of electric vehicles.Aiming at minimizing the total user charging cost,minimizing the sum of the peak and valley difference of each fast charging station and minimizing the sum of the variance of daily load curves of each fast charging station,the constraint equation is proposed considering the actual situation,and the improved firefly algorithm is applied to solve the optimization model.The simulation results show that the proposed optimization strategy can effectively reduce the total charging cost of users,reduce the peak and valley difference of fast charging stations,and reduce the fluctuation of daily load curves.