Identification of Interacting Power System Dynamic Phenomena via Continuation of Invariant Subspaces

This paper will focus on identifying the interacting dynamic phenomena in power systems by using continuation of invariant subspaces (CIS). With this approach one can trace the trajectory of different oscillatory modes as system parameter changes. Many power system dynamic phenomena, such as strong resonance, subsynchronous resonance (SSR) et al., are related to the interaction of oscillatory modes. First, the eigenvalues corresponding to these modes are associated with their invariant subspaces. By applying the continuation method, eigenvalue trajectory with parameter variation can be obtained from the CIS method. The numerical results on the New England system and IEEE SSR first benchmark model are illustrated in detail. Different interacting dynamic phenomena are identified. The interaction of the oscillatory modes will be demonstrated too.