Identification and control of inter-area modes

Inter-area oscillations in power systems are becoming common occurrence due to loading increase of tie-lines. Their control is crucial to maintain stability of the system. This paper addresses the identification of the inter-area modes by classifying the modes as local or inter-area using controllability and observability indices. Then power system stabilizers are considered for the control of these modes. Feasibility of control structures is determined using high order residues. A large size system with 9 control areas and 19 generators is used to illustrate the proposed methodologies