A Coordinated Multi-Time Scale Robust Scheduling Framework for Isolated Power System With ESU Under High RES Penetration

Abstract

Renewable energy resources (RESs) have been considered to be a promising solution for providing clear and economical power in isolated islands. Due to the low predictive nature, conventional unit commitment with a deterministic optimization algorithm is no long suitable for grids with high RES scale. This paper proposes a coordinated multi-time scale robust scheduling framework for isolated system with energy storage units. The framework decomposes the adjustable dispatch process into three coordinated stages and specifies the operational policy of thermal and hydraulic units. We formulate mathematical models for each dispatch stage and add additional constraints for inter-stage coordination. Then, we develop a multi-stage robust solution based on Bender's decomposition and a cutting plane algorithm. Finally, we test the proposed framework with real data from Nanji Island, China. Compared with traditional scheduling, robust schedule approach can significantly improve the “robustness”of grids and allow higher RES penetration level.

Keywords

• Adjustable robust optimization
• multi-time scale framework
• isolated island
• renewable energy resources
• high RES penetration
• seawater pumped storage system