Distributed Charging Control for Electric Vehicles Considering Fair Power Allocation

With the increasing penetration of intermittent renewable energy sources (e.g., photovoltaic and wind generations), more reserve energy is needed to deal with the fluctuations in power supply, which increases the cost of electricity energy. In addition, the deployment of electric vehicles (EVs) further stresses the grid. In this paper, we study a smart charging problem for a network of electrical vehicles using a distributed method to counter the fluctuations in the power supply. A three-level controller is proposed. The top-level controller provides a feasible charging schedule based on the forecast power supply, EVs' initial and target state-of-charge (SOC) levels and their required plug-off times. For the middle-level controller, we develop a distributed control algorithm that adapts the charging rate of each EV to the fluctuation of power supply while providing a fair dispatch of the available power to all EVs. The bottom-level controller uses the frequency deviations to correct the difference between the forecast power and actual available power. The features of the proposed method are demonstrated using a bank of Lithium-ion batteries with ADVISOR models.