Modeling Of Charging And Discharging Behavior Of Electric Vehicles And Study On V2G

With the increase of vehicle population, a large number of exhaust emission becomes one of the important causes of air pollution,as a result,the haze weather occurs more frequently,it makes people pay more attention to environment issues. At the same time, when the petroleum, the fossil energy is consumed heavily every day, the advantage of electric vehicle, such as it uses the clean energy without exhaust, has been widely noticed. The large application of electric vehicles has already become a inexorable trend. Large amount of electric vehicles will bring several problems when they are charging, and also, electric vehicles can be treated as the power storages that can be moved anytime. If they can be used in a proper way, the popularity of electric vehicles will be coming soon. In this paper, we suppose that electric vehicles are largely used in our society, and then the impact on the power grid while they are charging or not is researched as well as the impact on power quality of the grid when they are treated as moved power storages.Firstly, in this paper, the origin and significance of this subject, the development of electric vehicles, the modeling methods of their charge and discharge characteristics and the model of V2G are discussed. Secondly, the modeling of charge/discharge characteristics of electric vehicles is presented and simulated in this paper using Monte Carlo method under three conditions:not controlled charging, controlled charging and V2G After that, the impact on the daily load curve of the grid under three conditions mentioned before is got. Thirdly, under SIMULINK condition, the V2G system model which can transmit power to both sides while electric vehicles connecting the grid is built, and the corresponding control method is presented. Lastly,the experiment is performed on the electric vehicle platform. The influence on the grid harmonic is analyzed when electric vehicle invert the power to the grid under different current conditions.The simulation results of charging/discharging behavior of vehicles show that:firstly, vehicles’participation will enlarge the difference between peak and valley under the uncontrolled model; secondly, in controlled model, the participation of them will decrease the difference between peak of valley of the grid; thirdly, the goal of peak load shifting is easily achieved under the V2G model, under this model, the exchanging power between vehicles and the grid will contribute on the load balance of the grid. The results of the V2G model built in SIMULINK condition show that the current,voltage of the inverter output contain harmonic, directly affect the power quality of the grid after electric vehicles access the grid. The results of batteries discharging experiments on the experimental platform show that the battery inverter will cause the harmonic, and when the output current is increasing, the harmonic get smaller.