Considering the Energy-Flexible Market Two-Stage Distributed Clearing Method of Transmission and Distribution Network for Optical Storage System

[Objective] With the continuous increase of flexibility resources in distribution networks， they can now participate in flexibility markets to provide active and reactive power flexibility support for transmission networks （TN）. This study thoroughly explored flexibility resources in distribution networks and proposes a two-stage distributed energy-flexibility market-clearing method for transmission-distribution networks， considering photovoltaic storage systems to enhance grid operational flexibility. [Methods] First， a PV storage system model was constructed by integrating energy market mechanisms with active and reactive power flexibility market mechanisms and analyzing its potential for active and reactive power support. Second， a two-stage market-clearing model for transmission-distribution networks was developed with the objective of maximizing the overall economic efficiency. Third， to preserve the privacy of the TN and distribution network information during computation， the proposed model was solved using the Alternating Direction Method of Multipliers （ADMM）. Finally， the method was validated using a test system that couples an IEEE 30-bus transmission network with two 33-bus distribution networks. [Results] The results show that when distribution system operators （DSO） participate in flexibility market transactions， the procurement costs for active and reactive flexibility resources in the TN decrease by 7.93% and the flexibility supply-demand balance index improves from 4.021 to 5.736. [Conclusions] The proposed method enhances the economic efficiency of the system， effectively reduces the total cost of procuring active and reactive flexibilities， and supports operational stability. Additionally， active distribution networks （ADN） can leverage their abundant active and reactive flexibility resources to provide flexibility services to transmission system operators （TSO）， thereby increasing ADN revenue and enabling the optimal allocation of flexibility resources across the grid. This study demonstrates the feasibility of coordinated flexibility trading between transmission and distribution networks under high renewable energy penetration conditions.