A Measure for Nearly Decentralized Fixed Modes using High Order Residues

In this paper, high-order residues (HiORs), a generalization of the classical residue concept, are defined. Two different ways to compute HiORs are presented. These HiORs are then used to derive general high order eigenvalue sensitivity expressions. Also a measure to assess Decentralized Fixed Modes (DFMs) and Nearly DFMs (NDFMs) is obtained in terms of HiORs. This measure is significant in determining mode shift under uniformly bounded feedback gains. A 32nd order power system is used to illustrate the proposed methodologies. When compared to some existing methods, the proposed approach gives better results.