Scheduling of electric vehicle charging request and power allocation at charging stations with renewable energy

Smart grid, a concept proposed in 2003, is now attracting more and more attention because of its ability to integrate intensive information and renewable energy generating infrastructures. This paper focuses on scheduling charging process between multiple electric vehicles and charging stations in smart grid with renewable energy and storage devices. From the perspective of the whole system, the goal of minimizing the time average electricity cost with time-varying electricity price can be reached in this paper. With the participation of storage devices, charging-station-private renewable generation and electric vehicles power demands, we mathematically formulate a stochastic optimal problem and address it by employing Lyapunov optimization methods. Through mathematical derivation, stability of storage devices is achieved. Meanwhile, the upper bound for time average electricity cost can be calculated. The feature of our research is the independence on stochastic distribution of demand and renewable generation. Simulation results show the convergence of storage device state of charging (SOC) and illustrate the efficiency and performance of our algorithm.