Coordinated Optimazation Strategy for Electric Vehicles' Charging and Discharging in Different Regions

The charging and discharging behaviors of electric vehicle (EV), as a kind of moving load, will have profound influences on the power grid. In order to alleviate these influences, we researched the coordinated optimization strategy for EVs' charging and discharging. In a certain region including residential region and industrial-commercial region, we firstly studied the load demand of EVs' charging and discharging under the circumstance of minimum load fluctuation and the minimum economic cost. Then, we explored the relationship between the total charge and discharge power of user and the electricity price. Finally, we guided the intermediary side guides users to coordinate charging and discharging through the rebating policy. The results show that power load variance of the grid side is greatly decreased and the total charging and discharging costs obtained by the intermediary side are increased after the optimization of charging and discharging load through multi-objective genetic algorithm. The intermediary side will save costs to subsidize users, through the 0-1 optimization, reduce battery damage to save user fees, reduce waiting time for the user to bring convenience, while the intermediary side profits for reduced subsidy costs. Through the coordination of the grid side, the intermediary side and the user side can achieve optimization strategy of EVs' charging and discharging behaviors. The optimization strategy makes a complex optimization process to decompose into different modules, which not only satisfies the demands of every part but also makes the process more maneuverable. Finally, an example is given to verify the effectiveness of the proposed strategy. © 2018, High Voltage Engineering Editorial Department of CEPRI. All right reserved.