Distributed energy management for underground engineering microgrid with reliable power supply

Battery energy storage system (BESS) is of great significance to ensure underground engineering (UE) microgrid to have reliable power supply. Distributed energy management is one of the solutions that can enhance the microgrid reliability by efficiently scheduling the distributed appliances (such as diesel generator, BESS) to accommodate various scenarios. A distributed energy management model is proposed, which can help in reliable power supply by prolonging the lifetime of BESS and reducing the load loss. Considering the different energy consumption needs and dispatching capabilities of three regions of the UE microgrid, the proposed energy management model distributed dispatches the three regions in UE microgrid. In addition, considering the relationship between the depth of discharge and lifetime, the proposed energy management model also contains the BESS lifetime extension model constructed with dynamic charge-discharge rate and dynamic bidirectional AC/DC converter efficiency. Based on the deterministic optimisation method, the optimal solution of the proposed energy management model is obtained. The effectiveness of the proposed energy management model is validated under six scenarios (that is grid connected mode, off grid mode, partial interconnection mode, interconnection mode, and independent modes with and without power exchange). The simulation results demonstrate that compared with the conventional model, the proposed model can reduce the operation cost by 6.46% and the load loss rate by 0.747%, which helps to improve the reliability of UE microgrid.