Plug-and-play model predictive control for electric vehicle charging and voltage control in smart grids

This paper presents a predictive controller for handling plug-and-play (P&P) charging requests of electric vehicles (EVs) in a distribution system. The proposed method uses a two-stage hierarchical control scheme based on a model predictive control (MPC) formulation for tracking periodic references. The first stage computes a reachable periodic reference that trades off deviation from the nominal voltage with the required generation control. The second stage computes a controller that tracks this reference and charges the EVs, while satisfying system constraints at all times. Under the assumption of a time-periodic load, it is shown that the proposed controller is recursively feasible and exponentially stable i.e. the EVs´ state of charge (SOC) and bus voltages converge to the desired SOC and to the optimal periodic reference respectively. Finally, the proposed scheme is illustrated in a set of examples.