Research On Orderly Charge And Discharge Control Strategy Of Electric Vehicle V2G Technology

V2G(Vehicle to Grid)technology is a two-way flow of energy between the power grid and electric vehicles by combining power electronics,communication,dispatching and metering technologies.It is a comprehensive application system that can play the role of energy storage for idle electric vehicle batteries The battery discharges during the peak load of the power grid and charges the battery during the low load of the power grid,so as to relieve the pressure during the peak load of the power grid and realize the effective allocation of resources.The main research contents of this article are as follows:(1)First introduce the main types of new energy vehicles,and determine the research object is pure electric vehicles;then briefly introduce the power batteries of pure electric vehicles.Common power batteries mainly include lead-acid batteries,nickel-metal hydride batteries and lithium ion batteries,etc.,respectively.The charge and discharge principles and electrode reaction equations of the three power batteries are expounded,and then from the perspective of specific energy,specific power and cycle number,lithium ion batteries are finally selected as the power batteries of pure electric vehicles;The charging characteristics were analyzed to determine that the charging process of the lithium-ion battery of the pure electric vehicle was constant power charging;considering the influence of the depth of discharge on the cycle life of the lithium-ion battery,a classic theoretical battery loss model was established,and the battery participation V2G time list was calculated The secondary discharge cost lays the foundation for the user’s loss cost when the battery is discharged below.(2)A brief introduction to the three charging methods of electric vehicles,namely conventional charging,slow charging and battery pack charging,and determining that the charging method of electric vehicles is slow charging;then according to some data according to the US NHTS2009 database,The basic rules of charging behavior habits such as home time,time to leave and daily driving distance of electric vehicle owners are summarized,and their probability distribution function is determined;then a brief introduction to Monte Carlo simulation and the establishment of disordered charging load The model,according to the Monte Carlo simulation,obtained the total grid load of a certain area during the disorderly charging of electric vehicles on the Matlab platform.According to the analysis of the results,it can be seen that with the increase of the number of electric vehicles,the total load of the grid also rises and concentrates Peak load areas at night.(3)In order to alleviate the problem of electric vehicles focusing on charging during the peak electricity consumption at night,time-sharing electricity prices are introduced;under the effect of time-sharing electricity prices,a multi-objective with minimum load mean square deviation on the grid side and minimum charge and discharge costs on the user side is established The function model considers the constraints of the electric vehicle itself and the battery,formulates the relevant charging strategy and charging and discharging strategy,and uses the WCA algorithm to model the total load of the power grid in two scenarios;the analysis results show that the electric vehicle is in order Both charging and charging and discharging can effectively relieve the pressure on the grid caused by the concentrated charging of electric vehicles at the peak of electricity consumption.At the same time,the orderly charging and discharging of electric vehicles can achieve the minimum mean square deviation of the load on the grid side and the minimum cost of charging and discharging on the user side.With the increase of user participation,the optimization effect is more obvious.At the same time,the weights on the grid side and the user side are different,and the optimization results are also different.In general,electric vehicle V2G technology can reduce the grid load variance and user charging and discharging costs during the orderly charging and discharging of electric vehicles,thereby realizing the common interests of both parties.