Research On Operation Strategy Of Centralized Charging Station Considering Concentrating Solar Power And Battery Swapping Demand

In recent years,the sharing service of EV as a new type of sustainable transportation mode has attracted much attention.It depends on that multiple people to repeatedly use one electric vehicle and pays time or mileage to achieve intensive and green travel.Considering the advantages of convenient and quickness of battery swapping modes,the EV-battery swapping has become the dominant model for electric vehicle sharing services.The large-scale adoption of EV-battery swapping is inseparable from the supporting power supply facilities.The centralized charging station and the battery replacement point as a power supply mode based on battery swapping mode,can provide a good power supply service.The battery swapping point is responsible for quick battery replacement,and the replaced battery is uniformly slow charged and maintained by the centralized charging station.This method not only satisfies the fast power supply demand of the shared service object,but also prolongs the cycle life of the battery.However,the centralized charging of large-scale power batteries will result in excessively high power purchasing costs for centralized charging stations,and will cause adverse effects such as large load fluctuations and increased peak-to-valley differences in the power distribution system.For this reason,it is of great significance to carry out research on the operation strategy of centralized charging stations.First of all,since China's primary energy is still dominated by coal,oil,etc.,the clean energy using model of electric vehicles does not really depart from the dependence on fossil energy.Therefore,it is of great value to consider the joint operation of renewable energy generation and centralized charging stations.As an important renewable energy power generation technology,Concentrating Solar Power(CSP)mainly realizes conversion of light energy-heat energy-kinetic-energy electric energy through heat collectors,heat storage equipment,and steam turbine units.Compared with photovoltaic power generation,CSP uses heat storage equipment to achieve similar output characteristics such as good regulation performance and strong climbing ability of conventional gas turbines,and it can continue generating heat at night or without light periods.Therefore,this paper considers that CSP can provide stable and continuous output for centralized charging stations to meet the needs of battery replacement at the battery replacement point,reduce the purchase of electricity from the grid,and mitigate the impact of large load fluctuations and voltage drop on the distribution system.The CSP and centralized charging stations are used.Joint operation,DC integrated system,AC integrated system and AC-DC hybrid integrated system of CSP and centralized charging station are designed.The operation mode of CSP centralized charging station and battery replacement point is designed to lay a theoretical foundation for follow-up research.Secondly,an orderly charging and discharging strategy for centralized charging stations considering CSP and power exchange requirements is proposed.Based on historical data of one week/month prior to the battery replacement date,the maximum power exchange demand is calculated during the day.Under the conditions of satisfying the CSP operational constraints,system power conservation,and the maximum power exchange requirements within the day of battery replacement,a centralized charging station is built for daily purchase.The orderly charge-discharge model with the goal of comprehensive optimization of electricity costs and system load fluctuation penalty costs.Considering that the proposed model has non-convex,nonlinear,and high-dimensional mathematical properties,a new meta-heuristic intelligent search algorithm,Natural Aggregation Algorithm(NAA),is used to solve the model.Through examples,it is shown that considering CSP can effectively reduce the day-to-day power purchase cost and system load fluctuation penalty cost of centralized charging stations.Compared with considering photovoltaic power generation,CSP has better practical value and economic value in the actual operation of centralized charging stations.The configuration of the thermal storage equipment of the CSP has a nonlinear effect on the operating cost of the centralized charging station.That is,as the capacity configuration increases,the operating cost of the centralized charging station gradually decreases,and the effect tends to be saturated when the capacity configuration reaches a certain threshold.Finally,under the background of the gradual release of the electricity sales market,the decision of the centralized charging stations to participate in the distributed operation of the distributed energy trading system is studied,that is,a more economical operation plan is realized through the power interaction between the centralized charging stations.Taking into account the randomness of the light intensity and demand for power exchange,a stochastic programming model was constructed with the objective of minimizing the integration cost of the daily charging power grid of the centralized charging stations,the interactive power purchasing cost between the centralized charging stations and the system load fluctuation penalty cost.Considering the independent decision of the centralized charging station,a distributed optimization algorithm based on Distributed Alternating Direction Method of Multipliers(D-ADMM)is proposed to solve the proposed model.Through examples,it is shown that the centralized charging station group has better economical performance in the summer when compared with the winter season;the coordinated operation of the centralized charging station group is more economical than independent operation;the proposed distribution optimization algorithm based on D-ADMM has a consistent solution effect with the centralized optimization algorithm.