Hierarchical optimization control strategy for electric vehicle in active distribution network

Coordination managing and controlling the various intermittent energy, energy storage, and controllable load, active distribution network can increase the ability of renewable energy interconnection to distribution network. In this paper, considering the randomness of charging time and the fluctuation of intermittent energy output and load, an electric vehicle charging control strategy based on hierarchical optimization of active distribution network is proposed. On the decision layer, within long-time scale, optimization plan of electric vehicle charging is calculated based on the car charging information, the prediction of load and the intermittent energy on the feeder line. The optimization goal of the charging plan is to reduce the feeder exchange power fluctuation. On the terminal layer, within short-time scale, the charging pile adjusts the charging power in real time according to the feeder control error, so the feeder exchange power will keep stable near the optimal value. Eventually, a case study shows the effectiveness of control strategies.