Improvement of OPF Decomposition Methods Applied to Multi-Area Power Systems

Large power systems are nowadays mostly operated as interconnected subsystems, each not always based on identical legislative, historical and geographical regulations. Within this interconnection, each power system is controlled by its respective control authority, forming a decentralized structure. In this paper methods are presented, decomposing a central optimal power flow (OPF) problem into distributed subproblems. These subproblems are then solved in an iterative way, independently but coordinated. Based on an available decomposition method, an improved decomposition procedure is proposed. With the new method, the convergence rate is considerably enhanced and no parameter tuning is required. Simulation results are presented, applying the procedures to an illustrative 9-bus as well as to the IEEE 39-bus system.