Research On V2G Electric Vehicle Charging Station And Grid Connection Technology

With the accelerated process of industrialization, the shortage of resources andenvironmental pollution are growing obviously. The exhaust produced by ordinary fuelvehicles is a major source of urban pollutions and the fuel cars consume a lot of oilresources. Nowadays, as the people realize the importance of environmental protection,the development of low-carbon transport has become an important issue faced by thegovernments. Under these conditions, the electric vehicles have emerged.The advantages of electric vehicles are environmentally friendly, clean, no(low)pollutant emissions. So it is the main direction of new energy vehicles in the future.Electric vehicle charging stations based on the V2G(Vehicle to Grid) technology supportbi-directional energy interaction between grid and electric vehicles. The energy flow fromthe grid will be injected into the battery when the battery needs to be charged. While theelectric vehicle is in a suspended state, the energy will flow from electric vehicles to gridso as to improving the energy utilization. This dissertation firstly introduces thebackground and development status of the V2G technology. Its signification and purposeare also included in this article. Composition and function of the charging systems areanalyzed comprehensively as well as the development of charging equipments.The power battery with the charging station is introduced. On this basis, thedissertation discusses the battery charging-discharging principles, charge-dischargemethod, the overall electrical structural configuration and distributed system design of thecharging stations. In this condition, the peak load shifting strategy is also achieved. Themain circuit topology of electric vehicle charging stations based on V2G function includesa three-phase voltage-source PWM rectifier and a bi-directional DC/DC converter. Thedifferent charging-discharging theory and control strategy are carried out simultaneouslyin MATLAB/Simulink as well as the parallel operation mode and the discharging processin grid single-phase short circuit situation. It can be seen from the simulation results thatthe energy flows in bi-direction between the grid and electric vehicle power batteries,while ensuring that the current of the grid side is sinusoidal, current haronmic is suppressed and the power factor is approximately1.Finally, the experimental devices and system hardware are designed according to thetheoretical simulation studies and the main power components are selected. A prototype isproduced and the overall system control strategy is implemented through the DSPsoftware programs. The charging-discharging experiment is completed, which verifies thecontrol strategy.