Natural decomposition of interconnected power systems for stability Studies

The paper describes the development of a decomposition method which exploits the structure of large power systems. As large power systems are almost invariably composed of weakly connected subsystems, each consisting of strongly interacting machines, the proposed decomposition technique provides, by analysing and quantifying the dynamic interactions among the generating units on the basis of a linearised model, a natural subdivision which reflects the structural features of the system. The method is rigorous and can be carried out systematically. The resulting decomposition scheme can be used to simplify the stability analysis of large power systems under both small and large disturbances. The capability and the usefulness of the proposed method are illustrated by carrying out simulation studies on a sample power system.