The data provides supporting material for the two case studies in Chapter 5 of CoordiNet D6.2 (the deliverable is available at https://coordinet-project.eu/publications/deliverables) and the two case studies in paper on TSO-DSO cooperation (available at https://arxiv.org/abs/2111.12830). The dataset is cooresponding to two case studies. In the first case study, the interconnected system consists of the IEEE 14-bus (TN) transmission network connected to three distribution networks: the Matpower systems 18-bus (DN_18), 69-bus (DN_69), and 141-bus (DN_141). The interface flow limit is TPmax. In the second case study, the interconnected system consists of the IEEE 14-bus (TN) transmission network connected to three Matpower systems 18-bus distribution networks, who are named as DN_1, DN_2, DN_3. All systems topology and some parameters are based on the corresponding cases in Matpower [1]. Base demand is adapted from the case, while base generation profiles are added to all nodes. All distribution systems are balanced, and the transmission system is imbalanced. Thermal limits of the lines are adapted in order to create congestion in the systems. Each distribution system is connected to the transmission system through one line. The interconnected system is fully represented in "Network_XXX.xlsx", in which: System: transmission (TN) or distribution (DN_XXX); LineID: ID of the lines; BusNumber: number of the nodes within the systems. This parameter is used to define the lines (from/to); BaseDemand and BaseSupply: base active demand and generation of each node; ConnectedDN: distribution system to which the transmission system node is connected to. If blank, the node is not connected to any distribution system. Only for the transmission system; InterfaceCapacity: thermal limit of the interface between the transmission and distribution systems; ThermalLimit: thermal limit of the transmission/distribution systems lines. For distribution systems, a value of 10 indicates that the line has no limit; SFTN: shift factor matrix of the transmission system. Capture the change in the active power flow over a line due to a change in injection or offtake at a node; BaseReactiveDemand and BaseReactiveSupply: base reactive demand and generation at each node. Only for distribution systems; VoltageLB and VoltageUB: lower and upper limits for the magnitude squared of the voltage in each distribution system node. Only for distribution systems; ConnectedTN: identify if the distribution node is connected or not to the transmission system. Only for distribution systems; ResistanceR: resistence of the distribution system lines. Only for distribution systems; ReactanceX: reactance of the distribution system lines. Only for distribution systems. Flexibility bids are randomly generated in the different nodes. For downward flexibility bids, the prices are drawn from the uniform distribution in the range 10 to 15, and for upward flexibility bids, they are drawn from the range 50 to 55. The bids maximum quantities are generated according to the base demand or supply of the node from which they are connected.. The generated orderbook is presented in "OrderbookTN_XXX.xlsx" (transmission system) and "OrderbookDN_XXX.xlsx" (distribution systems): OrderID: the ID of the order, to make each order unique; System: the system (TN, DN_XXX) from which the order is offered; BusNumber: the node from which the order is offered; FlexibilitySense: UPWARD for increase in generation or decrease in demand; DOWNWARD for increase in demand or decrease in generation; Price: the submitted order price; Quantity: the maximum quantities of the order. Source of the systems' topology: [1] R. D. Zimmerman, C. E. Murillo-Sanchez, and R. J. Thomas, “Mat-power: Steady-state operations, planning, and analysis tools for power systems research and education,” IEEE Transactions on power systems, vol. 26, no. 1, pp. 12–19, 2010. Please notice that this dataset does not replace the information provided by Matpower related to the aforementioned systems. It rather uses those systems topology and some of their parameters to build a case study to investigate TSO-DSO coordination market models for the procurement of flexibility. For the full description of these systems, please visit: MATPOWER – Free, open-source tools for electric power system simulation and optimization.