Analysis of sustained interarea oscillations in power systems using kinetic energy approach

In this paper, an energy approach to analysis of sustained interarea oscillations (SIAO) in power systems has been developed. SIAO is characterized as oscillatory behavior, following a disturbance, of the rotor motion with respect to it synchronous reference frame, for two or more generator groups such that there is a periodic interchange of energy between them. A proper coordinate framework is necessary for analysis of energy interchange. We can identify generators exchanging energy during SIAO using phase of kinetic energy expression in synchronous coordinate framework. By comparing the phase of the coefficient of the dominate energy node in the kinetic energy deviation for each generator, we identify the groups for which there are periodic interchanges of energy. The location of these groups in the system provides insight regarding transmission lines over which the energy interchange is taking place. The numerical result of the test system shows that the approach results in improved understanding of the SIAO phenomenon