Research On Grid-connected Control And Real-time Optimal Scheduling Of Electric Vehicle Cluster Based On V2G Technology

With the rapid development of Electric Vehicle（EV）,the integration of EV into the grid technology（Vehicle-to-grid,V2G）is becoming a power grid peak regulation tool that cannot be ignored.Electric vehicles can not only absorb energy from the grid side as a load（Grid-tovehicle,G2V）,but also serve as a distributed power source to feed back energy to the grid to participate in peak regulation.Focusing on the power shock,harmonic pollution and the reasonable distribution of power in the charging process of the electric vehicle V2 G system in the process of grid connection,this thesis has made an in-depth study.With the sharp increase in the number of electric vehicles and random distribution,in order to facilitate unified scheduling on the grid side,this thesis constructs a grid-connected structure of electric vehicle clusters,and the electric vehicles in the region participate in the grid regulation in a cluster manner.Due to the obvious changes in the capacity of the electric vehicle cluster,the insufficient inertia of the grid-connected power in the V2 G process has an impact on the power grid.This thesis adopts a virtual synchronous generator control strategy for the cluster-connected inverter to increase the grid-connected damping of the electric vehicle cluster and reduce the grid fluctuation.Aiming at the problem that the vibration link of the virtual synchronous generator control strategy causes the harmonic superposition,which makes the grid-connected electric vehicle cluster seriously pollute the power grid harmonics,a harmonic suppression strategy based on the virtual synchronous generator technology is proposed.Starting from the virtual synchronous generator control mechanism,the harmonic characteristics of the system under the condition of grid-connected electric vehicle clusters,it is proposed to extract the main harmonic components through frequency division harmonic extraction technology,and perform high-slope droop control on each main harmonic component to quickly clean up the harmonics output by the grid-connected inverter.It can improve the harmonic suppression capability of grid-connected inverters for electric vehicles.The simulation model of the electric vehicle cluster V2 G system is built under the Matlab/Simulink platform.The control of the grid-connected inverter adopts the virtual synchronous generator control and the third and fifth harmonic frequency division droop control respectively.The simulation results show that the virtual synchronous machine control strategy And the frequency division droop control strategy can effectively improve the control performance of electric vehicle cluster grid connection.In order to better coordinate the peak regulation effect of electric vehicle clusters,a power distribution scheme for electric vehicles for the purpose of shaving peaks and filling valleys is proposed in G2 V mode.Introducing the concept of charging station agent,combined with the idea of master-slave game,aiming at maximizing the interests of charging station agents and minimizing the cost of charging the car owner as the game goal,combining Karush-KuhnTucker conditions and linear programming,the nonlinear optimization The problem is converted into a mixed integer linear programming algorithm,which is solved by Matlab software and Cplex+Yalmip solver,and the game results are optimized.