Electric vehicles are both transportation means and mobile loads. Their large-scale and intensive charging will impact the transportation network and the power grid at the same time. In view of EVs' mobile attribute，their charging demands can be optimized in time and space dimensions through the vehicle-to-grid（V2G） technology. The technology can not only alleviate the aforementioned impact， but also provide energy storage capacity to the power grid，so as to promote the accommodation of renewable energy resources and peak load regulation of the power grid. Taking a charging station invested by State Grid Corporation as the example， a siting and sizing strategy for the charging station that considers transportation and power networks is proposed. On the premise of satisfying the charging demands of electric vehicles， the strategy optimizes the charging demand to maximize the energy storage capacity of the station. Firstly， based on the dynamic traffic network model， the driving paths of electric vehicles are accurately simulated by Floyd algorithm and regional characteristics，to predict the spatial and temporal characteristics of electric vehicle charging loads. Secondly，based on the prediction results， the preliminary station location is determined by three goals，maximizing the energy storage capacity，smoothing the charging load， and the extending the parking time in the station. Then， the optimal location and capacity of the charging station are adjusted according to the statistical results from the whole period. Taking the roads in a main urban area as an example， the spatial and temporal characteristics of the charging load are predicted， and the optimal location and capacity of the charging station aiming at maximizing its energy storage capacity is designed. The influence of this design on the transportation network and power grid is analyzed，which proves the effectiveness of the proposed strategy.
