Energy and flexibility markets clearing mechanism for electrical distribution system through a flexibility imbalance modification strategy

• A joint energy and flexibility markets framework is constructed to motivate FROs to participate in market trading varieties. • This paper establishes an adaptive joint market clearing model to balance economy and the flexibility. • A market pricing model considering flexibility support costs is developed to transfer these costs to the demand side. The high proportion of new energy connected to the grid leads to a surge in the demand for flexibility in the distribution network, and the contradiction of insufficient system regulation capacity is becoming more and more prominent. The current market mechanism relies on a single electric energy transaction, which fails to reflect the regulation value of flexibility resources. Thus, this paper establishes a joint energy-flexibility market clearing mechanism for distribution system based on flexibility modification. Firstly, the framework of the joint energy-flexibility market is designed to incorporate flexibility into the market transactions and to enhance the participation of market participants through multiple revenue channels. Secondly, an adaptive joint market clearing model is established to dynamically modify the flexibility supply–demand gap to achieve a balance between economy and flexibility, and the power flow sensitivity factors are introduced to accelerate the convergence of the modification iterations. Furthermore, a market pricing model that takes into account the flexibility support costs is developed to realize the transfer of flexibility costs to the demand side and to incentivize the energy-flexibility supply–demand dynamic equilibrium relying on price signals. Finally, case studies based on the improved IEEE-14 and IEEE-69 test systems are performed to verify the effectiveness of the proposed model.