Topological characteristic studies on power system small signal stability region

Abstract

Topological characteristics of the power system small signal stability region are tentatively studied in this paper. First, some necessary background theories on nonlinear dynamic system and small signal stability region are briefly reviewed. Then, we present an example that there exists a hole (instability region) inside the small signal stability region. Theoretical study is performed to find the cause of this phenomenon based on bifurcation analysis. It is found that occurrence of the hole in the small signal stability region is caused by a 2-order degenerated Hopf bifurcation, while breaking of the hole is caused by concurrence of two Hopf bifurcations. Studies of this paper are helpful to understand the topological characteristics of the small signal stability region in power systems