This paper presents a coordinated approach to provide power grid flexibility in cooperation with transmission system operator (TSO) and distribution system operator (DSO) in the context of day ahead (DA) electricity market. Considering the constraints of distribution network, the DSO submits an aggregated power–cost function using a non-iterative approach that substantially reduces the computational burden of the upstream market clearing, while preserving the essential economic characteristics of the distribution system. In this function, the costs of generations connected to distribution network are obtained by considering the uncertainties of renew- able resources using a robust budget approach. This function, in fact, provides the TSO market operator with a range of active power along with their related costs. After the energy market clearing, the amount of power exchanged at the TSO-DSO connection point is notified to the DSO. Since the power-cost functions announced by the DSO are carried out taking into account the constraints of the DSO network, the market clearing results are always feasible, and the market no longer encounters the problem of infeasibility. The framework of the pro- posed coordinated market is such that the DSO does not need to forecast the upstream market price. The simplicity of the proposed market implementation increases the speed of market clearing and high adaptability to existing markets. The results from the simulation of the Nordic-60 Bus test network demonstrate the effectiveness of the proposed method well.
