Study On The V2G System Of New Energy Vehicle

With the development of science and technology,now the ownership of new energy vehicles continues to grow,of which electric vehicles accounted for half of the country.How to interact electric vehicles with the power grid has become a major research hot spot.V2G(Vehicle to Grid)technology embodies the two-way interactivity between the power grid and electric vehicles.To achieve the electric vehicle power back to the grid,inverter technology is mainly important,and the key to achieving the inverter is bi-directional converter.In this paper,on-board charging and discharging circuit system is discussed and studied based on the vehicle-mounted converter.In this paper,the background of the topic and the meaning of the topic are discussed.The basic structure of V2 G is analyzed and introduced.The research status of V2 G at home and abroad is introduced.The technical requirements of vehicle charging and discharging circuit system are proposed,they are energy two-way flow,the appropriate control strategy and high efficiency.A two-stage charge-discharge circuit topology was established.The former AC/DC converter and the post-stage DC/DC converter were analyzed and designed respectively.Finally,a full-bridge AC/DC converter circuit was established.It works.After analyzing the basic ZVS principle of the basic DC/DC converter circuit,a basic two-phase interleaved Buck/Boost converter circuit is designed and analyzed,and its working principle is analyzed.The control strategy of vehicle charging and discharging circuit system is studied.Based on the basic control strategy,a control strategy based on virtual dq coordinate system is proposed,which can realize independent control of active power and reactive power of single-phase rectifier.The control strategy of single-phase rectifier DC/DC circuit.According to the equivalent model of the battery and the requirements of charge and discharge,a unified control strategy of current and voltage dual mode is proposed,which can simplify the whole control.Based on the above theory,the parameters of two-stage bi-directional charging anddischarging circuit are designed and calculated.Respectively,the former two-way AC/DC converter and the DC/DC converter after the main circuit parameters were designed and calculated.On the basis of the preceding datas,their controller parameters were calculated for the next chapter of the simulation Analysis.The V2 G simulation model is built and the control sub-modules of the former and the following are analyzed.In the steady state,the three modes of constant voltage charging,constant current charging and constant current discharging were simulated and analyzed respectively,and the inverter function of V2 G was realized and it meets the requirement of two-way energy flow.Also,the efficiency of charge and discharge was improved.On the basis of the simulation results,the system has good dynamic performance and meets the requirements of the on-board charging and discharging circuit system.