Analysis Of Operational Benefits Of Optimal Charge And Discharge Strategies For Electric Vehicle Substations

The popularization of electric vehicles depends on large-scale power charging and exchanging infrastructure construction,while the power exchanging station in the charging and exchanging mode possesses such advantages as no consideration to battery logistics delivery,small power supply capacity needed by the power station,no reliance on power exchanging station construction and relatively low investment cost,especially is suitable to serve as the service supporting infrastructure at the early stage of promoting electric vehicles.The model construction of electric vehicles and power charging and exchanging station has already possessed certain operation basis in various pilot cities in China after recent years'model city construction of electric vehicles.To better realization of the electric vehicles power charging and exchanging infrastructure marketization,it is needed to make systematic technical economic analysis of the electric vehicles power charging and exchanging station and the key factors that affecting its operation,and analyze the influence of its operation and management on the power grid load based on ensuring the economy.Only afte ensuring the operation main body of electric vehicle supporting infrastructure produces economic interests can it attract more investment,join in infrastructure construction,remove customers' worries of the power supply sources of electric vehicles,raise the consumers' motivation to buy electric vehicles and then promote electric vehicles development.First,this paper introduces the basic theory of linear programming and four commonly used solution methods.Then,the characteristics and application occasions of three commonly used charging modes are compared and analyzed,and the advantages and disadvantages of the power exchanging stations of two power exchanging modes are also compared in this paper.Then,the operation and profit modes of the power exchanging station of electrical vehicles are analyzed on the basis of time-sharing pricing mechanism,and the profit function of the power station is also established according to that.Furthennore.the linear optimization model of the best power charging and exchanging strategy of the power exchanging station are established based on certain simplified and hypothetical conditions,with taking the maximum profit of the power station as the objective function and also considering the constraints of the balance of battery quantity,the number of full quantity of electricity batteries,the number of empty batteries and the number of charge lattices.Next,taking the operating status of a hypothetical electric vehicle power exchanging station in one day and the BAIC EV200 parameters of the power exchanging vehicles as the basic data,this paper simulates the operation status and load status of power exchanging station under eight scenes.After getting relevant results and verifies the established models with two price pricing methods,it's proved that the maximum economic interests of the operation main body of the power exchanging station of electric vehicles are realized.Next,the operating factors like the power exchanging demand quantity changes at any time and the changes of these factors can affect the final profit of the power exchanging station at different degree,and through analyzing the sensitive parameters of the power exchanging station,it's found that:as for the power exchanging station,the sensitive parameters that affecting its interests are mainly the service fees of power charging and exchanging,battery depreciation fees and grid electricity price;as for the power grid,the sensitive parameters that affecting the peak load shifting of the power exchanging station are the total number of batteries and the number of charging lattices.Finally,the optimal amount of internal facilities investment in the power exchanging station is analyzed,and the corresponding annual revenue and yield rate are acquired.The optimization model put forward in this paper can provide decision-making basis for the commercial operation of the power exchanging station.The results of study is conducive to the operation side of the electric vehicles to acquire the maximum economic interests and this study can also provide basis for power grid management department to manage and schedule the power exchanging station.