By using bidirectional AC-DC power converters to interface the grid with the plugin electric vehicles (PEV) batteries, the vehicle-to-grid (V2G) approach is enabled. By this approach, the PEV batteries can work as distributed storage systems that deliver electric energy to the grid under peak power requests. In addition, the battery-converter set can be exploited to execute ancillary functionalities such as to stabilize the grid voltage by injecting reactive power and to improve the power grid quality by filtering current harmonics and by balancing the line currents. This paper presents at first some possible scenarios for the application of the V2G approach. Then the functionalities offered by the V2G approach are addressed. An improved controller is applied in order to achieve low input current harmonics. The Proportional resonant controller is utilized for the V2G mode. Compared with conventional PI controllers, the proposed controllers greatly enhance the grid connected converter’s performance in the aspects of low harmonics output.
Electric vehicle, Vehicle-to-Grid, Bi-directional converter,Proportional resonant controller