Global swing instability in the New England power grid model

Global swing instability is an undesirable and emergent phenomenon of synchronous machines in a power grid, implying that most of the machines in the system simultaneously lose synchronism with the rest of the grid after being subjected to a finite and local disturbance. Recently we reported that global instability occurred in the classical model of swing dynamics in the New England power grid model. This paper analyzes the global instability in the New England power grid model. We show that the proper orthonormal decomposition and the Galerkin method for model reduction can determine a dynamical mechanism responsible for the global instability. These methods applied in this paper make it possible to find the occurrence of global instability in real power grids.