The Related Study On Impacts And Utilization Of Large-scale Electric Vehicles Integration Into Power Grid

As the deterioration of environment and the crisis of energy, electric vehicles have been developed greatly, and the integration of the large-scale electric vehicles to the grid inevitably will have a great impact on power system. The dunb charging of large-scale electric vehicles will cause problems such as overload, increasing voltage deviation. While smart charging can transfer load and even discharge to the grid, which can improve the security and economy of power system.So the impacts and utilization of large-scale electric vehicles integration into power grid is worthy of study. This paper gets into the study by modeling the electric vehicle load, researching the adaptability of grid for electric vehicles and electric vehicles schedulable capacity etc. The main research work includes the following content.This paper firstly analyzes the electric vehicle charging load influence factors, and the users travel rule is researched by probability and Markov chain respectively. From the perspective of the probability to research a method to forecase vehicle charging load based on Monte Carlo. Then the dumb charging, TOU price charging, and the smart charging strategy are analyzed separately. Two smart charging models whose goal respectively is to smooth the load fluctuation and reduce the abandoned wind are established. And the simulation verifies the effectiveness of the models.According to the influence of large-scale electric vehicle on power grid, this paper studies a method to evaluat the adaptability of distribution network with large-scale electric vehicles integration. The probability of power flow is calculated based on probabilistic load of electric vehicle. And then the adaptability of distribution network is evaluated from four aspects including the network load, power loss, voltage deviation, and the maximum allowable scale of electric vehicle etc. And the influence of three different charging strategies of electric vehicles on distribution network is compared. This method can provide the basis for the electric vehicle scale accessing to the grid and distribution network planning and operation.Then, according to the electric vehicles have the potential to provide ancillary services to power grid, firstly the operation mode of electric vehicle participating power grid control is analyzed. Then it respectively propose a real-time schedulable capacity evaluation method of large-scale electric vehicle for for V1 G and V2 G control mode, based on user demand and battery life. The schedulable capacity evaluation method of electric vehicles can be used in peak regulation and frequency regulation and other ancillary services, so it has a certain practical value.