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Optimal Operation Of Distribution Network Considering V2G With Distributed Energy Resources

Posted on:2020-10-05Degree:MasterType:Thesis
Country:ChinaCandidate:Z MeiFull Text:PDF
GTID:2392330578982890Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
Being driven by energy,environment and government policies,electric vehicle(EV)industry is ushered in a period of rapid development.Meanwhile,it becomes a current tendency with the parallel operation of clean distributed energy resources(DER).Benefits can be brought with EV and DER.However,some questions are brought,too.Disordered charging of EV and the fluctuation of DER may do harm to a distribution network.To reduce the influence,a study on optimal operation of distribution network considering V2 G with DER is proposed.The main contents and results of this paper are as follows:(1)A operating strategy of distribution network considering V2 G based on grouping method of EV is proposed to reduce the influence.A internal and external nested model is built based on two aspects of macroscopic system and network topology.Cost of owners,standard deviation of distribution network and network losses are considered as objectives.In this model,DER,distribution network and EV are optimized correspondingly.The optimal operating states can be get by the coordination of vehicles and the resource.To meet owners' mobility needs,a grouping method is proposed based on two eigenvalues,which are the moment of starting to charge and the time that is needed to get owners' expected state of charge.Thus,dimensions of variate are decreased.Case analyses in four scenarios are solved.The strategy is proved to ensure benefit of owners,decrease load level,stabilize load fluctuations,abate difference of peak and valley load,improved voltage level and reduce network losses.(2)EV and DER may do harm to the current protection of distribution network.To ensure proper action of protection and reduce the influence of disordered charging of EV and fluctuation of DER,a optimal operating strategy is proposed.This strategy is based on the coordination of EV and DER considering current protection.To improve efficiency,a strategy of cluster control is used to solve a optimal model.This model is built without changing the original protection schemes based on information fusion nodes.Standard deviation of load and cost of owners of EV are considered as objectives.Optimum scale of EV is assessed based on dominant and recessive indicators of current protection and the indicator of voltage.The optimum operating states can be get by the coordination of EV and DER on the optimum scale.The strategy is proved to ensure benefit of owners and proper action of protection anytime during optimal cycle by case analyses.And the strategy is also proved to maintain voltage at normal range,stabilize load fluctuation,decrease load value and reduce network losses.(3)There is a certain error with the forecasting of power of DER and load.The plans of EV charging and discharging may be changed because of a temporary arrangement of car using.Therefore,a real time optimal operating strategy on the basis of MPC is proposed.Based on the research of cooperating strategy of EV and DER considering current protection,the plans of EV are amended.The real time optimum operating states can be get and day-ahead plans can be followed with the strategy.And the strategy is also proved to ensure indicators of current protection and the indicator of voltage in the limit by case analyses in three scenarios.Furthermore,EV owners' cost can be reduced on a certain degree.
Keywords/Search Tags:Electric Vehicle, Distributed Energy Resource, Grouping Method, Current Protection, Model Predictive Control
PDF Full Text Request
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