Research On Charging And Discharging Control Strategy Of Electric Vehicle Charging Piles Based On V2G Technoligy

With the energy crisis and environmental pollution problems and other issues have become increasingly serious, Energy sustainable development needs increasingly strong, electric vehicle technology came into being, which has become a hot topic in the current research. The continuous development and progress of modern science and technology, the number of electric vehicles has increased dramatically, and charging piles have become more and more.V2G is a two-way flow of energy between the electric grid and electric vehicles. This article select Iphotovoltaic grid to power the V2G charging pile, Because PV grid energy saving and environmental protection. When the power grid is in a very unstable moment, the energy can be back to the grid from the electric vehicle, power grid stable performance and safety performance will be greatly improved. It expands the use of new energy sources, make the human society towards saving, environmental protection and social development, can make people better to enjoy the advantages of electric energy.We select the topology of V2G charging piles which is made of a three-phase half bridge voltage-source PWM rectifier and a bi-directional DC/DC converter. Firstly, We introduce the three-phase half bridge voltage-source PWM rectifier,and a detailed analysis of how it works, mathematical models and control strategy. After analysis and research, under dq synchronous rotating frame, the voltage space SVPWM with voltage-current double closed loop will be adopted. Secondly, the bi-directional DC/DC converter is discussed in its working principle and topology.Lastly, In the simulation environment, build the simulation model of the whole system, and analyses the results of the simulation,introduces the PV.The simulation results are as follows:in the process of charging, the grid side current is sinusoidal, and its phase and the grid voltage is the same; Electric vehicle in the discharge process, the grid side current is sinusoidal, but its phase and the grid voltage is opposite, that is,180 degrees, DC bus voltage is very stable, the dynamic performance of the system is also very good, it can achieve function of V2G.The digital signal processor of TMS320F28335 DSP is designed as the core of the control system, the whole control system has carried on the designed hardware and software,the results show that the V2G charging pile can achieve unity power factor correction, and can realize two-way flow of energy, improve the stability of power grid.