Generator Modeling in the Context of Small-Signal Stability

Modal analysis is the well-established method for investigating small-signal stability. Dominant states of a particular oscillatory or monotonous mode can be identified by linearizing the system's differential equations. Since generator oscillation is predominantly influenced by the speed deviation and the rotor angle, whereas other state variables play a minor role, an approach to reduce a generator's state matrix to a lower order is presented in this paper. Fundamental, analytical investigations concerning generator modeling of synchronous generators connected to an infinite bus ensure the correct reproduction of the generator's electromechanical behavior without losing accuracy compared to higher-order models.