The photovoltaic charging station for electric vehicle to grid application in Smart Grids

The number and variety of EVs batteries connected to grid continue to grow rapidly, which result in a heavy burden on grid. To solve this problem, it was proposed that electric vehicles could act as a new power source for grid, which is the concept of Vehicle to Grid (V2G). This paper proposed the photovoltaic charging station architecture by using a combination of the Z-source boost converter based on the battery charging strategy with the bi-directional PWM Inverter-Rectifier based on the V2G strategy in Smart Grids. In the photovoltaic charging mode, the PV arrays charge the battery by the Z-source boost converter. In V2G mode, the PWM Inverter-Rectifier transfers the active power and passive power according to the grid requirement, thus the EV batteries could be applied for the peak regulation and frequency regulation in grid. Also the EV battery could be used as storage system for renewable power system. The prototype of bi-directional PWM Inverter-Rectifier and Z-source dc-dc converter is developed. Finally, V2G and battery storage experiments are tested. Meanwhile the Z-source dc-dc converter voltage boost experiments are tested. Simulation and experiment results demonstrate that the prototype implements the power bi-directional transformation between power grid and electric vehicles, and the Z-source dc-dc converter achieves the voltage boost. Consequently V2G could significantly increase the smart gird system flexibility, and storage intermittent renewable energy from wind and solar.