A framework for estimating flexible resources according to future Korean renewables scenario: Robust optimization approach considering multiple uncertainties

This study presents a robust optimization model to secure flexibility under a high penetration of renewable energy systems in a future grid. An increase in renewable energy into a power system causes difficulties and complexities with regard to power system planning and operation owing to an increase in uncertainty. This trend can create an issue in the flexibility of a power system under a high penetration of renewable energy. To acquire sufficient flexibility, numerous flexible resources such as conventional generators with a ramping capability, energy storage systems and demand response program should be procured. Herein, we propose estimating the flexible resource capacity required to prevent a flexibility deficit when considering multiple uncertainties such as the effective capacity and 1-min power fluctuation rate of the renewable energy systems. To solve this problem, including uncertainties, through an optimization technique, we adopt a robust optimization to deal with uncertainty by constructing an uncertainty set and provide a robust solution considering the worst case within such a set. The robust optimization model was tested using data from the Korean electric power system for the year 2030. In addition, the results from a robust optimization are compared with the results from a deterministic approach.