Research On V2G Technology Of Electric Vehicle And It’s Charging System

As the energy shortage and environmental issues more and more serious,Electric vehicles become a national focus on the development of new energyvehicles, With the increasing number of electric vehicles, the impact on power gridof battery charging is also more and more should not be ignored. At the same time asthe electricity load peak-valley difference is more and more large, various countrieshave built many dedicated peak and frequency modulated power plant. If use thestopped EVs for power peak and frequency modulation through grid connectioncharge and discharge, it will reduce the specific power plant investment andconstruction, V2G technology emerges.Firstly, this thesis summarized the research status of the V2G technology, Bycomparison, a new realization based on Charger-Swap Station is the most effectiverealization at the primary stage of V2G，analysis the advantages of the form basedon charger-swap station. On this basis, the particle swarm optimization (pso)algorithm is adopted for V2G in order to realize charge and discharge orderly. Builda grid frequency modulation model based on charger-swap station. Verified suchform of V2G have faster frequency adjustment ability through simulation results.In the realization process of V2G, Bidirectional charger is indispensableequipment. Against no mature bidirectional charger, this thesis compare and analyzethe charger’s main circuit topology firstly, In how to realize the bidirectionalcharge-discharge and inhibition of current distortion, analysis the charger’stopology theoretically, Current control strategy based on hysteresis and the spacevector control strategy are adopted to build bidirectional charge and dischargesimulation model of two type bridge structure, simulation results are displayed.Based on thorough analysis two kinds control strategy and under the charger-swapstation occasion, realized independent control of active power and reactive powerunder single phase power supply, in turn, it can participate in reactive powercompensation, and achieved that the current doesn’t influenced by distortion in thecase of grid voltage distortion, and the dc side voltage can also effectively suppressfluctuation under the case that there is a change in the input voltage amplitudethrough introducing the virtual coordinate control system.Finally, developed a charging system, using the method of Active Power Factor Correction (APFC), realized the output voltage controllable and unit power factoroperation in grid side.