Research On Electric Vehicle Charging And Discharging Scheduling Strategy Under Time-Sharing Tariff Mechanism

Electric vehicles are an effective means to alleviate the energy crisis and promote the development of a low-carbon economy due to their advantages of high energy efficiency and low pollution,and they are also a new direction for the future development of the automotive industry.On the one hand,as a large-capacity load,the charging and discharging behavior of electric vehicles is highly random and uncertain due to the influence of users’ living habits and travel patterns.On the other hand,as an energy storage device,electric vehicles can feed power to the grid to assist the grid to improve its operational efficiency.On the other hand,as a kind of energy storage device,EVs can feed into the grid to improve the efficiency of the grid.The regulation of EV charging and discharging behavior is inevitably based on economic considerations,and the time-sharing tariff mechanism,as a flexible economic regulation tool,can,to a certain extent,guide EVs to make reasonable arrangements for charging and discharging time and mode.Therefore,this paper revolves around the above-mentioned issues and the main content includes:(1)Analyzing the relevant characteristics of electric vehicles,focusing on the influencing factors such as charging mode,battery characteristics and user behavior characteristics of electric vehicles,and simulating their disorderly charging loads by using Monte Carlo probability sampling method.Through the analysis of the simulation results,we can see that the charging load of EVs in the disorderly charging scenario coincides with the base load in time distribution,which will produce the phenomenon of "peak on peak" and further expand the peak-valley difference,which will adversely affect the safe,stable and economic operation of the power system.(2)Based on the principle of peak-valley time-sharing tariff and considering the battery loss factor of electric vehicles,an orderly charging and discharging scheduling model is constructed with the optimization objectives of minimizing the charging and discharging cost of electric vehicles,minimizing the battery loss cost,minimizing the peak-valley difference of load curve and minimizing the mean square difference of load under the peak-valley time-sharing tariff mechanism.The dispatching model is solved optimally by using genetic algorithm.The effectiveness of the proposed scheduling strategy is verified under the peak-valley time-sharing tariff scheme by comparing with the fixed tariff scheme.(3)Improving on the peak-valley time-sharing tariff,a dynamic time-sharing tariff model is proposed,which linearizes the relationship between tariff and load.In addition,considering that EV access to the grid will have an impact on network loss and voltage stability,an orderly charging and discharging scheduling strategy with the lowest cost of EV charging and discharging,the lowest amount of change in network loss,and the lowest amount of change in voltage stability index is constructed,and a sensitivity analysis method is used to quantitatively evaluate the impact of EV load access on the grid,and the voltage stability constraint is taken into account,and through multiple scenario comparison The effectiveness of the orderly charging and discharging scheduling strategy under the dynamic time-of-use tariff mechanism is verified through multiple scenario comparison analysis.The proposed scheduling strategy takes the voltage stability factor into account,which can provide reference for the analysis of the impact of EV charging stations on voltage stability under the actual grid.