Hierarchically Adaptive Frequency Control for an EV-Integrated Smart Grid With Renewable Energy

With the technology development of intelligent power generation and consumption, more and more electric vehicles (EVs), smart loads, and renewable energy are linked up to smart grids. In this paper, due to the great response ability of EVs, a large number of aggregate EVs are considered to improve the frequency response. From this point of view, for an EV-integrated smart grid with loads and renewable energy, a novel hierarchically adaptive control strategy is developed including both the primary controller and the EV controller when power mismatches happen. The sliding-mode primary controller is used to stabilize the frequency by operating power plants, while the EV controller is designed by using adaptive dynamic programming to deal with most of the frequency deviation. Simulation is validated on a benchmark smart grid by comparative studies to demonstrate the superior performance of hierarchically adaptive frequency control as well as the benefit of using EVs in the frequency regulation.