Hierarchical Charge Control of Large Populations of EVs

Cooperation between the controllable load, such as electrical vehicles (EVs) and the generation, provides the power system new operating strategies. A novel hierarchical charge control framework is proposed based on the Benders decomposition for large populations of EVs. The grid, unit, and accurate EV constraints can be considered. On the upper level, the cooperative dispatch scheme between the generation and the EV aggregators is obtained. On the lower level, the feasibility of the scheme is checked with EV constraints considered. The levels are coordinated by the Benders cuts. In addition, the distributed approximate Benders cuts is also proposed, which helps to protect user privacy and a three-level framework is developed based on the decentralized control. The case studies on IEEE Reliability Test System have verified the proposed framework and method is valid and feasible. The charge control based on it can minimize the grid operation cost and improve the unit operating efficiency.