Research On The Impact Of Electric Vehicles Charging Behavior On Power Grid And Optimization Strategies

Compared with traditional fuel vehicles,electric vehicles have higher energy efficiency and lower carbon emissions,and have the potential to replace traditional fuel vehicles.Countries around the world are vigorously promoting the scale of electric vehicles.With the increasing permeability and charging power of electric vehicles,strong randomness of charging behavior of individual electric vehicle poses severe challenges to the safe economic operation of power grid.As charging stations is a buffer between electric vehicles and power grid,the reasonable construction and operation of charging stations is crucial for coordinating the relationship among electric vehicle users,power grid and operators.And it can guide the charging behavior of electric vehicles.The contradiction between charging behavior of electric vehicles and power grid,as well as the mitigation strategies based on charging stations are deeply studied.The main research contents are as followsFirst of all,the charging behavior characteristics of electric vehicles are analyzed from the dimensions of space,time and power.And these characteristics are verified based on historical electric vehicle charging data.Then multi-peak Gaussian mixture distributions are fitted for the charging behavior of different electric vehicle models in one day.The Monte Carlo method is used to simulate the charging process of electric vehicles in IEEE33 distribution network,and its impact on power grid operation is analyzed through power flow calculationSecondly,an optimization strategy for the location and capacity of charging stations is proposed for improving grid operation.The studies use queuing theory to simulate the operation of charging stations and predict the spatiotemporal charging demand distribution of electric vehicles simultaneously.Then an optimization model is established with the objective function of maximizing the comprehensive operators'profit including the power generation cost of grid.The generalized Benders decomposition algorithm is used to solve the mixed integer nonlinear programming problem.The simulation results verify that this model can greatly improve the comprehensive operators' profit on the basis of meeting the user's charging needs and grid constraints.The rationality of the model and algorithm is verified through simulation.Finally,a dynamic pricing optimization strategy of charging stations is proposed to minimize power loss and voltage offset during grid operation.Adjusting the price can lead the shift of users' charging demand and change the load state of grid nodes.The changing result lead the change of grid's power flow and improve the random impact of charging behavior on power grid operation.The rationality of the model and algorithm is verified through simulation.