Distributed Economic MPC for Synergetic Regulation of the Voltage of an Island DC Micro-Grid

In this paper, distributed model predictive control (DMPC) for island DC micro-grids (MG) with wind/photovoltaic (PV)/battery power is proposed, which coordinates all distributed generations (DG) to stabilize the bus voltage together with the insurance of having computational efficiency under a real-time requirement. Based on the feedback of the bus voltage, the deviation of the current is dispatched to each DG according to cost over the prediction horizon. Moreover, to avoid the excessive fluctuation of the battery power, both the discharge-charge switching times and costs are considered in the model predictive control (MPC) optimization problems. A Lyapunov constraint with a time-varying steady-state is designed in each local MPC to guarantee the stabilization of the entire system. The voltage stabilization of the MG is achieved by this strategy with the cooperation of DGs. The numeric results of applying the proposed method to a MG of the Shanghai Power Supply Company shows the effectiveness of the distributed economic MPC.