Coordinated Control Strategy for Microgrid in Grid-connected and Islanded Operation

Abstract

AC/DC Hybrid Microgrid is the main trend of microgrids. Efficient energy management and optimization is not only the primary means of ensuring the economic operation of microgrid but also the key of the realization of “Plug-and-Play”. Aiming at this problem, this paper proposed an optimization strategy for hybrid microgrid with energy storage and controllable micro-source which is based on distributed Predictive Control (MPC). The proposed algorithm is composed of several MPCs which are distributed in every generator and operate parallel. Power balance constraint and voltage amplitude constraints are designed to coordinate each individual MPC controller for balancing power supply and demand, and ensuring the power quality, respectively. The perturbation of renewable energy is suppressed by state feedback and receding horizon optimizing. In addition, the power loss of the connection converter is also taken into account, which is different from other types of microgrids. Finally, the simulation results show the effectiveness of the proposed method.