Analyzing the effect of the type of terminal voltage feedback on the small signal dynamic performance of synchronous generators

This work presents a thorough study about the effects of the type of terminal voltage feedback in the dynamics of a power system that can be modeled as a single machine (synchronous generator) connected to an infinite bus. As is presented in this paper, the type of terminal voltage feedback employed directly affects the dynamic performance of power systems when they are subjected to load unbalance, and hence, if the terminal voltage is not correctly defined, the behavior of the system can be completely different than the one predicted by the linear or nonlinear analysis. The main motivation for such a study is to better understand the behavior of power distribution systems with typical topology when distributed synchronous generators are present, which is common in several countries around the world. The focus of this paper is the dynamic behavior of the system after small perturbations, as characterized by the system eigenvalues representing the electromechanical oscillations. All the analyses are carried out through the estimation of these eigenvalues via a rotational invariant technique (ESPRIT method) from nonlinear simulations performed using the Alternative Transients Program.