Abstract

This paper presents an energy management system (EMS) with demand-side management (DSM) capabilities to optimally coordinate multiple microgrids connected to the same main grid. The proposed EMS comprises a two-level hierarchical control structure, with local controllers at microgrid level, and a supervisory control at the main-grid level. The main contribution of the proposed EMS is that it uses model-based predictive controllers (MPC) and DSM at both levels of the hierarchy. The main-grid level minimizes the imported power from the main grid and the shift from the expected demand for each microgrid. Moreover, it computes optimal aggregated power and demand side management references for each microgrid. The microgrid level manages the energy resources of each microgrid based on the reference signals sent by the main-grid level. Thus, the microgrid level tracks the main-grid level references, while minimizing both the power variation in the battery energy storage system and the variation in shifting factor to manage the demand. A simulation of a multi-microgrid system with three microgrids is implemented to validate the performance of the proposed two-level hierarchical MPC-based EMS with DSM. The proposed control scheme uses fuzzy Takagi-Sugeno models to predict the generation and consumption of the microgrids at both control levels. Furthermore, the proposed configuration is compared with two conventional EMS from the literature. The proposed architecture outperforms previously proposed controllers since, in the considered simulations, it (i) reduces to at least 1/4 the loss-of-power-supply probability for each individual microgrid, (ii) halfs the cycling of the individual storage devices in each microgrid, and (iii) reduces the overall system cost in similar to 1.5%.