Research On Charge And Discharge Technology Control Method Of Electric Vehicle Based On V2G Mode

With the sustained development of new energy technologies,electric vehicles and wind power generation and photovoltaic power generation have emerged in real life.However,due to the shortage of existing distribution transformers’ capacity,it is difficult to transform and increase the capacity of switching circuits.If a large number of electric vehicles are be charged by connecting to the existing power grid in a randomized and messy way,this will inevitably cause the grid voltage amplitude to fall,and the charging will superimpose the peak load of the grid,which will increase the power supply pressure of the grid and affect the stability of the power system.During the past few years,with the increasing penetration rate of distributed power sources,the V2G technology has gained a wide range of attention.Considering that V2G technology can provide the power grid with active and reactive power support,load balancing,and complementary and synergistic functions with renewable energy,this paper conducts the research of electric vehicle charge and discharge control mode based on V2G technology.First of all,to achieve the complementary and synergistic function of electric vehicles and renewable energy in V2G mode,this paper contrasts and analyzes three common control methods of distributed power grid-connected inverters,and then establishes voltage and current double closed loops by combining the mathematical model characteristics of voltage-type grid-connected inverters.Secondly,this paper studies the grid-connected strategy of the virtual synchronous machine to control the inverter,which enables inverter simulate the working characteristics of traditional synchronous motor mathematically and then achieve friendly interaction between electric vehicles and the power grid.This technology works by enabling the inverter mathematically simulate the traditional synchronous motor.Finally,considering that the intermittent power of distributed power sources cannot meet the needs of grid stability,this control strategy of complementary and collaborative output of electric vehicles and distributed power generation based on MPC(Model Predictive Control)is studied to realize the correction of real-time active power demand of electric vehicles and further protect the stability of grid operation.To sum,Matlab2018a/Simulink,a simulation model based on a virtual synchronous generator control inverter,is established to verify the effectiveness of the above control strategy.According to the Matlab/Simulink analysis results,electric vehicle grid-connected inverter employing integrated synchronous generator technology control can enable electric vehicles to change the magnitude and direction of electric vehicle active power and reactive power by combining rated frequency and voltage amplitude fluctuation.The rated frequency changes the magnitude and direction of the active power required by itself,so as to realize the active support to the power grid.In addition,on the basis of the virtual synchronous generator control inverter,a MPC simulation is established,which can improve the stability of power grid by realizing real-time adjustment of the electric vehicles’ active power demand according to the output changes of distributed power generation.