Decentralized Coordinated Tie-Line Scheduling Based on Decomposition Methods in Case of Multiple Markets

The growing demand for electric energy and the increasing penetration rate of renewable energy sources have led to the development of regional electricity markets internationally. In this paper, decentralized power exchange scheduling methods are discussed, in terms of tie-lines of interconnected areas, where each area has a separate electricity market. These methods include auxiliary problem principle (APP), optimality condition decomposition (OCD) and alternative direction multiplier (ADM), and it has been tried to compare different aspects of the operation to identify their efficacy under different conditions. The comparisons made in this paper are more comprehensive than previous studies and it has been tried to identify the positive aspects and challenges of each method with respect to network conditions and the superior method for coordinated scheduling of the tie-lines is determined. Simulation studies have been performed on a three-area (triangular structure) test system to create a loop between the intersecting tie-lines. Also, different tie-line capacities between the areas and different choice of references buses are considered. The efficacy of these methods in each case is described.