Cooperative Optimization of Energy Storage Capacity for Renewable and Storage Involved Microgrids Considering Multi Time Scale Uncertainty Coupling Influence

The high uncertainties of renewable generation and load demand complicates the capacity optimization of the energy storage in microgrid system. This paper proposed an explicit approach to the optimal capacity of the energy storage in grid-connected microgrid system, where the stochastic uncertainty and the forecasting error uncertainty of the renewable generation and load demand were simultaneously considered. Two types of indicators (i.e. energy balance ability indicator and robustness coordination cost indicator) were proposed with planning and operation purposes, respectively. In particular, under the premise of fully considering the coupling effect of energy storage capacity planning and microgrid system optimization operation, the studied optimal energy storage capacity problem was formulated as a two-stage collaborative optimization model. Then, a compound differential evolution algorithm was induced to solve the two-stage collaborative optimization model efficiently. Numerical simulation results demonstrate that the proposed approach can ensure that the microgrid system operates in a economical and grid-friendly manner. © 2019 Chin. Soc. for Elec. Eng.