Optimization of Energy Storage Capacity Allocation in Microgrid Systems for Industrial Parks

An optimization strategy for storage capacity is proposed to enhance operational efficiency and maximize local renewable energy usage in industrial park microgrids. This approach is designed to balance energy sources and loads, thereby reducing operational costs and enhancing grid stability. Firstly, a microgrid structure incorporating sources, grid, loads, and storage is constructed. To cope with the fluctuations in grid frequency and voltage due to the integration of wind and solar power, simultaneously storing as much new energy generation surplus as possible. The objective function is constructed to minimize the total cost of electricity purchase, energy storage investment, and the cost of wasted wind and solar energy. Constraints such as power balance, storage output, and wind and solar outputs are considered to optimize the rated capacity and power of storage and initial state of charge <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(SOC)$</tex>. Then, simulation analysis of a typical day's operation data from a specific park microgrid is done, which shows that different initial states of charge significantly impact the system's operating costs and energy shortage rates. An initial SOC of 0.9 results in the lowest operating costs and energy shortage rates, confirming the importance of properly setting the initial charge state to enhance the economic efficiency and stability of the microgrid.