Study On The Impact Of The Large-scale Electric Vehicles On Power Grid And The Countermeasures

With the energy crisis and increasing environmental pollution,energy-saving emission reduction has been imperatived.Due to its excellent characteristics,electric vehicles have drawn wide attention from people and its large-scale development will be an inevitable trend.Firstly,with the increasing number of electric vehicles,large-scale disordered charging of electric vehicles will have a non-negligible impact on the grid;Secondly,the development of Vehicle-to-Grid(V2G),bring some opportunities for operation of the power grid.Therefore,it has become an increasingly urgent issue to study the influence of large-scale electric vehicles which access on the power system,especially for low and medium voltage systems and optimize strategies.Electric vehicle charging can be seen a random load,the load model by many factors.This dissertation mainly pay more attention to the influence of users habit and battery characteristics,and discuss the influence of disordered charging of electric vehicles with the distribution network under different permeability.The main research contents are as follows:1.This dissertation introduces the calculation method of electric vehicles charging load,considering the factors such as battery characteristics,charging mode,user behavior and so on,and carries out the specific behavior modeling,and then simulates the charging load of electric vehicles based on Monte Carlo method.On this basis,the influence of electric vehicle charging on the node voltage is qualitatively analyzed.Then,based on the distribution network of a city of 10 kV,the electric vehicle charging load has quantitative effect on node voltage under different permeability.Finally,the simulation results are verified by the software of DIGsilent Power Factory.2.Electric vehicle's randombehavior will deteriorate micro-grid load curve.Traditional real-time price oriented control method does not make the electric vehicle charge and discharge has improved.In this dissertation,based on the game theory strategy,using the functional and satisfactory convexity utility guides the electric vehicle to charge and discharge independently and weaken the real-time electricity price utility,which provides a new direction for the optimization of the operation of electric vehicles.It is the simulation that helps to achieves the peak load shifting effect on,the electric vehicle,which provides the theoretical guidance for the electric vehicle to improve the power quality of the grid.