Research On Optimal Strategy Of Electric Vehicle Charging And Discharging Under Peak-valley Time-of-use Tariff

As the electric vehicles have the advantages of environmental protection and energy saving,it is an inevitable trend to develop electric vehicles instead of traditional ones.If large-scale electric vehicles are connected to the power grid,the disorder charging will bring great pressure to the power system.Therefore,the research of charging and discharging strategy optimization of electric vehicle under time-of-use price is of great significance to these issues:optimizing load curve,reducing the adverse impact on the grid,and improving income of the orderly participation of charge and discharge of electric vehicle owners and grid.In order to study the mathematical rule of charging and discharging of electric vehicle,the analysis on the division of time-of-use price and traffic rules of electric vehicles is analyzed,and the probability function of daily running distance and daily travel time of electric vehicle is obtained.The charging and discharging model and power expectation model of the electric vehicle under the condition of disorder and order charging and discharging are constructed,and the maximum discharge duration model of electric vehicle and the mathematical expression for selecting the time point of sequential charge and discharge are obtained.According to the power expectation curve of electric vehicle,it is necessary for the owner of electric vehicle to respond to the time-of-use price to reduce the peak load of the grid.To consider grid revenue,electric vehicle owners income and optimize the peak load of grid sufficiently,the time-of-use price period division and user response degree are taken as decision variables,the multi-objective optimization model is established which takes maximum profit of grid and electric vehicle owners and the minimum peak load as the objective function.Through the example simulation analysis of the relationship between the user response degree and the peak load,the optimal solution set of the grid revenue and the electric vehicle owner income is calculated under different user response degree and time-of-use price period,and the relationship between income of the electric vehicle owners and power grid is clarified.The effect of charging and discharging on the peak load of the grid under different user response degree and time-of-use price period is analyzed.The influence of two seasons in EV ordered charging and discharging of the typical daily load curve were discussed respectively.Comparing profits of electric vehicle owners and grid and peak load,before and after typical day adopting time-of-use price in two seasons separately..The results provides a decision basis for the best division of the time-of-use price period,maximizing the economic benefits of electric vehicle owners and grid,incentiving electric vehicle owners to actively participate in the orderly charging and discharging,optimizing the load curve and peak load shifting,which is of great significance.