Distributed Coordinated Clearing Strategy for Transmission and Distribution Networks in Energy and Flexibility Markets

This paper presents a distributed coordinated clearing strategy to facilitate the procurement of energy and flexibility in transmission and distribution networks. This strategy targets 15-min flexibility requirements of energy systems. Inspired by European market practices, a two-stage distributed clearing framework coordinated the transmission system operator (TSO) with distribution system operators (DSOs) is established. TSO and DSOs are responsible for transmission-level and distribution-level energy and flexibility markets, respectively. In the proposed framework, the energy and flexibility markets operate in a coordinated manner and are cleared sequentially, thereby optimizing flexibility procurement for both the transmission network (TN) and active distribution networks (ADNs) to meet the 15-min flexibility requirements of the power system. The alternating direction method of multipliers (ADMM) is used to solve the proposed distributed model while protecting the privacy of all stakeholders. Numerical simulations on a revised IEEE 30-bus transmission with two 33-node ADNs demonstrate that the proposed strategy improves system flexibility provision while enhancing the economic performance of both the TSO and DSOs. Specifically, compared with the decoupled transmission–distribution operation mode, the proposed method can not only reduce the TSO’s flexibility procurement cost by 22.4% but also increase the profits of DSOs by $3066.5.