Quasi-Steady-State Modeling of Interarea Oscillations

The subject of this paper is the extension of QSS modeling to include low frequency interarea oscillations in power system long-term dynamics. All other electromechanical oscillations, such as local or intra-area are replaced by equilibrium (algebraic) equations. Modal analysis and simulations are made on a classical test system of 11 buses and 4 generators. The effect of solver parameters and generator models on simulation results is investigated. Modal reduction is applied to Automatic Voltage Regulators and Speed Governors resulting in four different simplified models. A comparison is made between extended QSS and detailed modeling, focusing on the accuracy of the interarea mode frequency and damping.