Frequency Reserve Allocation of Large-Scale RES Considering Decision-Dependent Uncertainties

Abstract

The proliferation of renewable energy sources (RES) imposes significant challenges on system frequency dynamics. By synthetic inertia and droop control, RES units can provide fast response to sudden frequency events. However, the reserved power and available power of RES units are featured as decision-dependent uncertainties (DDUs), posing challenges to both post-contingency frequency security and system balancing under normal conditions. This article develops a frequency-constrained unit commitment and reserve allocation (FC-UC&RA) model that co-optimizes the reserve allocation and energy dispatch among synchronous generators and RES units. An analytic frequency dynamic model is embedded in the FC-UC&RA problem to accurately assess the system's frequency performance under heterogeneous responses of synchronous and inverter-based units with limited reserve deliveries. To cope with the DDUs stemming from RES generation capabilities scheduled as reserves, a robust FC-UC&RA model is proposed and an adaptive column and constraint generation (C&CG) algorithm is developed to solve the DDU-integrated robust optimization. Comparative case studies verify the effectiveness and applicability of the proposed model and solution approach.