A comprehensive review of coordinated operation of transmission‐distribution networks: Frameworks, problems and future trends

The rapid growth of distributed energy resources (DERs) is reshaping the operational landscape of transmission and distribution networks, creating new challenges for maintaining system-wide security, economic efficiency and flexibility. Transmission-distribution (T-D) coordination has emerged as an essential paradigm for facilitating multi-level interaction among system operators. This paper provides a comprehensive review of coordinated operation of T-D networks from four perspectives. First, it analyses key barriers related to market mechanisms, modelling and computational tractability. Second, it synthesizes the T-D coordination frameworks—centralized, distributed and sequential frameworks—and introduces models, including unit commitment, economic dispatch, online dispatch and control and feasible region computation. Third, it summarizes representative pilot projects from Europe, North America and Asia to illustrate current developments. Finally, persisting research gaps and directions are discussed. The review aims to provide a clear and organized understanding of existing knowledge while outlining a clear pathway for advancing the field of T-D coordinated operation.