Energy management framework for hybrid AC/DC microgrid with distributed energy resources

This paper proposes a centralized supervisory energy management strategy for hybrid AC/DC microgrid with multiple renewable energy (RE) sources. Energy management in the microgrid is challenging due to the stochastic and intermittent nature of renewable energy sources. These characteristics tend to cause the energy fluctuations in generation and load demand during peak, partial-peak and off-peak condition. The proposed algorithm considers framework to handle microgrid conditions such as peak, partial-peak and off-peak demand by developing an optimization problem using integer linear programming, linear programming and mixed integer linear programming. A supervisory energy management strategy (SEMS) is developed to coordinate among the sources such as solar photovoltaic (PV), wind turbine (WT), AC grid, battery energy storage system (BESS) and load for effective energy management. The proposed algorithm handles the uncertainties of PV-WT-BESS-based microgrid. Various test scenarios are performed to demonstrate the effectiveness of the proposed method, including load shedding operation, maximum utilization of renewable energy sources, minimal power import from the AC grid, DC bus voltage regulation and power flow balance. A 48 V DC, 1.8 kW PV-WT-BESS-based grid-connected DC microgrid is developed, simulated in MATLAB/Simulink, and it is demonstrated in a real-time simulator (OPAL-RT OP4510) to verify the proposed algorithm. Furthermore, the results of the real-time simulator confirmed the efficacy, reliability, and viability of the proposed algorithm under various operating circumstances.