Context: A major challenge of the ongoing energy transition relates to the fact that distribution networks, with increasing amounts of distributed renewable resources, are no longer only consuming power generated by the transmission network, but also producing power through distributed renewable resources (such as solar panels), and also hosting direct and indirect storage (e.g. in the form of deferrable demand or electric vehicles). According to the present paradigm, which is rapidly changing, one system operator is in charge of the high-voltage transmission network, the Transmission/Independent System Operator (T/ISO), whereas the distribution network typically absorbs the production. Distribution loads are aggregated at a transmission bus and the optimization of power generation is performed at the transmission level. In future operations, the Distribution System Operator (DSO) will need to assume a more active role in operating the network. There are various challenges in expanding the coordination of TSOs and DSOs. Technical requirements include scalability, communication, large-scale systems and non-linear network models. Institutional requirements include data sharing and legal constraints related to the roles and responsibilities of TSOs and DSOs.
Coordination schemes and clearing platforms: In the context of the EU Smartnet project, our team developed models for a variety of TSO-DSO coordination schemes. One scheme in particular, which relies on a hierarchical interaction between TSOs, DSOs, and the balancing market, is depicted in the left panel of the following figure. In ongoing work, we are implementing a market clearing platform that aims at achieving TSO-DSO coordination in the context of real-time market clearing (congestion management and balancing), while delivering scalability and accommodating non-linear network models and non-convex market offers. The proposed market clearing platform relies, as indicated in the right panel, on decentralized computation and minimal information sharing.
I. Mezghani, A. Papavasiliou, A Mixed-Integer Second Order Cone Program for Transmission-Distribution System Optimization, PowerTech, 2019
A. Papavasiliou, I. Mezghani, Coordination Schemes for the Integration of Transmission and Distribution System Operations, 20th Power Systems Computation Conference, Dublin, Ireland, June 11-15, 2018