Suppression of torsional oscillations using thyristor‐controlled conductance in parallel to series‐capacitor segment

Abstract

AbstractThis paper presents the analyzed results of a study on the application ofthyristor‐controlled conductance in parallel to one series‐capacitor segment for suppressing sub synchronous resonance (SSR) that occurs in a series‐compensated power system. The IEEE Second Benchmark Model, systems, which has one turbine‐generator set, is taken as a standard model for this study. In order to stabilize all SSR modes in the studied system, a unified approach based on modal control theory is proposed to design a damping controller which is a dynamic output feedback compensator using shaft speed deviation of the studied generator as a feedback signal. To demonstrate the effectiveness of the proposed control scheme, frequency‐domain approach based on eigenvalue analyses and time‐domain approach based on non‐linear model simulations are performed. The simulated results show that the proposed SSR damping scheme can effectively suppress torsional oscillations of the studied system.