A Hierarchical Energy Management Strategy for Grid-connected Microgrid

A novel hierarchical energy management strategy for grid-connected microgird is proposed in this paper. The proposed concept follows the idea of multiple time-scale coordination and consists of day-ahead layer, adjustment layer, and real-time layer. The day-ahead layer is based on look-ahead multi-step optimization techniques and the predicted availability of renewable energy sources. Future operational states of the controllable units in the microgrid could be determined ahead of time. The adjustment layer adjusts power output of online units by using the data at the dispatch time. Then, real-time layer is utilized to maintain the exchange power between the external macrogrid and the microgrid constant. In addition, energy storage plays a critical role in three dispatch and control layers. A typical microgrid system is simulated to demonstrate the performance and effectiveness of the proposed hierarchical energy management strategy.