Research on impacts of the electric vehicles charging and discharging on power grid

In the present, more and more concerns have been paid to the world energy conservation and environmental protection, therefore, the development of electric vehicles(EVs) are speeding up. Electric vehicles have good environmental protection performance and can taking many kinds of energy as power the prominent characteristic, and electric vehicles are considered as green transportation for the 21st century. Automotive manufacturers, governments, and environmental organizations are taking more and more care about the electric vehicle. As zero emission vehicles, electric vehicles can radically decrease vehicles exhausting pollution to improve air environment and adjust the energy structure. So, the author assumes that electric vehicles should be developed vigorously in our country, but large-scale EVs charging has become a practical problem in the grid operation and planning of the distribution network. It might have great impacts on the system performance, such as overloading, reducing efficiency, deteriorating power quality and increasing power system losses. As the light vehicle fleet moves to electric drive (hybrid, battery, and fuel cell vehicles), an opportunity opens for “vehicle-to-grid” (V2G) power. V2G only makes sense if the vehicle and power market are matched. This paper briefly discusses the impact of the charging on the distribution system, the factors of causing the influence, the charging control methods that reduce the impacts on the distribution network and V2G techniques. Based on the current development status and problems, discuss the trend of EV.