Application of perturbation methods to the analysis of inter-area oscillations

This paper presents some recent advances on the development of new techniques for the analysis and of inter-area oscillations in complex power systems. Two different approaches to assess the nature of inter-area oscillations are investigated and implemented in a production-grade computer program. The first consists of studying the nature of the motion modes of the system using conventional linear analysis. The second approach focuses on the analysis of nonlinear interaction under stressed operating conditions using the normal forms of vector fields. It is shown that the combined use of these methodologies allows a more physical insight into the nature of inter-area oscillations. The proposed methodology is tested on a 46-machine test power system with real characteristics