Smart routing of electric vehicles for load balancing in smart grids

Abstract

Electric vehicles (EVs) are expected to be a major component of the smart grid. The rapid proliferation of EVs will introduce an unprecedented load on the existing electric grid due to the charging/discharging behavior of the EVs, thus motivating the need for novel approaches for routing EVs across the grid. In this paper, a novel distributed control framework based on noncooperative game theory for routing of EVs within the smart grid is proposed. The goal of this framework is to control and balance the electricity load in a distributed manner across the grid while taking into account the traffic congestion and the waiting time at charging stations. The EV routing problem is formulated as a repeated game, and it is shown that the selfish behavior of EVs will result in a pure-strategy Nash equilibrium with the price of anarchy upper bounded by the ratio of the variance of the ground load to the total number of EVs in the grid. In particular, it is shown that any achieved Nash equilibrium substantially improves the load balance across the grid. Moreover, the results are extended to capture the stochastic nature of induced ground load as well as the subjective behavior of the EV owners using the behavioral framework of prospect theory. Simulation results provide new insights on efficient energy pricing at charging stations and under realistic grid conditions.