Research On Evaluation Network-Related Capacity And Interaction Mode Of Fast Charging Stations

With the continuous promotion of the "dual carbon" target,electric vehicles(EVs),as a clean and efficient means of transportation,have been increasing in number and play an important role in achieving the "carbon neutral" goal.The charging behavior of EVs is influenced by factors such as EV users’ travel patterns,charging prices,and road network conditions,which will increase the complexity of EV participation in regulatory interactions.Due to the high charging power,strong random characteristics of charging loads,and complex spatiotemporal distribution characteristics of fast charging stations(FCSs),the access of FCSs will further exacerbate the decline in network related capabilities such as power quality,road commuting capacity,and charging facilities utilization efficiency in the "EVs-road-network" system.A reasonable interaction mode can effectively improve the network related ability of fast charging stations,which is of great significance to alleviate the above problems.This article focuses on the evaluation and interaction mode of network related capacity of FCSs.The main work of this article is summarized as follows:1.Aiming at the decrease in the network related capacity of FCSs caused by EVs charging,a hierarchical comprehensive evaluation method for network-related capacity of FCSs is proposed.Based on an in-depth analysis of the operational characteristics of distribution networks,road networks,and FCSs,a hierarchical comprehensive evaluation architecture including target layer,rule layer,and index layer is established for the evaluation of the network related capacity of FCSs.At the index level,typical evaluation index for distribution networks,road networks,and FCSs are selected to achieve a description of the operational status of each system.At the rule level,the operational status of distribution networks,road networks,and charging stations is evaluated.Based on the scoring results of each indicator at the index level,system level status evaluation is realized.At the target layer,based on the evaluation results of each rule layer,the network related ability of the FCS is evaluated by the application of the fuzzy comprehensive evaluation method.And the hierarchical evaluation of the network-related capacity of the FCSs is realized.2.Combining the real-time operation status of road networks,FCSs,and distribution networks,a charging guidance strategy based on third generation prospect theory(PT3)is proposed.Firstly,the different operational state description models for road networks,charging stations,and power grids are established.Secondly,based on PT3,a dynamic multiple reference point selection method is proposed.A segmented simplified value function is established based on the dynamic multiple reference points.And prospect values are calculated based on the operating status of the "EVs-road-network" system.Fourthly,prospect analysis is performed based on the operating state of the "EVs-road-network" system.And the scheme is realized based on the maximum prospect value of FCSs.Finally,the simulation results show that the proposed charging guidance strategy can coordinate the distribution of charging loads among the FCSs,reasonably alleviate traffic pressure,and effectively ensure that the voltage of the distribution network is within the normal operating range.3.Considering the uncertainty of "EVs-road-network" operation state,an "EVs-road-network" robust dispatching strategy considering double uncertainties is proposed.Firstly,the optimal dispatching architecture of "EVs-road-network" system is proposed based on Stackelberg game.Secondly,considering the uncertainty of photovoltaic(PV)output,a day-ahead robust optimization model for distribution network is constructed to realize the optimization of distribution network operation cost in the leader layer.Thirdly,considering the uncertainty of travel time caused by road network traffic flow,EVs will participate in demand response based on the charging price established by the distribution network in follower layer.Finally,the simulation results show that the proposed optimal scheduling strategy can effectively reduce the operating costs of the distribution network,reasonably alleviate traffic operational pressure,and improve the operational efficiency of FCSs.4.For the "EVs-road-network" real-time operation optimization problem,a real-time charging pricing strategy based on cooperative game is proposed.Firstly,based on fuzzy evaluation,a real-time demand response model for EVs is constructed.By the application of the proposed demand response model,the preferences of EVs for charging prices and road conditions.Secondly,based on the cooperative game,a charging station cooperative alliance is established.And the revenue of each FCS can be allocated through the cooperative game on the basis of the locational marginal price and charging service fees to realize the formulation of charging prices.Finally,the simulation results show that by application of the proposed charging pricing strategy the negative impact of FCSs on the distribution network and road network can be reduced.And the network-related capacity of FCSs can be improved effectively.