Abstract:

The widespread integration of distributed renewable energy sources and virtual energy storage, such as electric vehicles, exacerbates the inherent uncertainty and low-inertia characteristics of power systems, thereby heightening frequency violation risks. Concurrently, the increasing flexibility and diversity of supply-demand dynamics within active distribution networks (ADNs) further complicate their interactions with transmission grids. To address these challenges, this paper proposes a novel power-carbon-green certificate distributed cooperative optimization framework based on the flexibility support mechanism of ADNs, with the objective of maximizing the utilization of distributed regulation resources and enhancing carbon reduction potential within integrated transmission-distribution (ITD) systems. Firstly, the dynamic frequency security constraints tailored to ITD systems and a flexibility support mechanism for ADNs based on interactive regulation modeling are established, forming a comprehensive ITD electricity-carbon-green certificate cooperation framework. To effectively address the uncertainty inherent in subsystems, joint chance constraints (JCCs) are employed to model the probabilistic nature of the problem. The Alternating direction of multipliers algorithm (ADMM) algorithm is adopted for the distributed cooperation of the transmission and distribution system. Case studies demonstrate the effectiveness of the proposed method in fully leveraging distributed resources and enhancing system frequency security. The framework also exhibits the ability to flexibly reflect the external support capacity or supported demand of ADNs. Compared to the transmission-grid independent dispatch model, the total operation cost is reduced by 13.42%, while renewable energy curtailment is decreased by 16.76% relative to the model that ignores multi-market coupling. These results demonstrate significant improvements in both the operational economy and low-carbon performance of the system. Furthermore, the proposed method achieves a reduction of approximately 98% in computational time compared to the traditional sample-average approximation (SAA)-based approach, thereby facilitating rapid distributed coordination within ITD systems.

Key words: integrated transmission and distribution dispatch, frequency security constraints, power-carbon-green certificate coupling