Optimal scheduling of renewable energy system based on probabilistic power balance under dynamic frequency security

Abstract

Aiming at the issues of reduced power system inertia, increased source − load uncertainties, and exacerbated frequency security risks caused by the integration of high − penetration renewable energy and power electronic devices, this paper innovatively prioritizes frequency security in dispatch decisions and proposes an optimal scheduling model that integrates dynamic frequency security constraints and probabilistic power balance. Specifically, a dynamic frequency response model incorporating wind turbines and energy storage is established, and a frequency security margin is introduced to convert frequency constraints into power constraints that can be directly embedded in the dispatch model. Meanwhile, based on the Wasserstein metric, the differences in the probabilistic distributions of source and load power are quantified, and a probabilistic power balance model is constructed to reduce supply − demand deviations. Ultimately, a multi − objective optimization framework is formed to achieve the coordinated optimization of frequency security and economic efficiency. Simulation verification shows that the proposed model can control frequency deviations within the safety threshold (reducing the maximum deviation by 0.23 Hz compared to the unconstrained scenario). Compared with traditional deterministic models, the total cost is reduced by 15.7%, and the wind curtailment cost is reduced by 22.1%. Additionally, when the frequency security constraint and probabilistic balance act synergistically, the system achieves the optimal comprehensive benefits, with an additional 6.6% reduction in the total cost. This provides an effective solution for the secure and economic dispatch of power systems with high penetration renewable energy under the bidirectional uncertainties of source and load.