A simulation-based analysis of subsynchronous resonance with TCSC

Abstract

In this paper a time-domain simulation-based SSR analysis has been carried out in PSCAD/EMTDC employing the IEEE first-benchmark system with thyristor-controlled series capacitor (TCSC). Though torsionalmode detuning behavior of a TCSC is well known its tuning performance for certain firing angles is demonstrated employing modal-speed evaluations. An attempt has been made to understand this nature of TCSC by obtaining its frequency response characteristics using frequency scanning technique. From the results it is inferred that the equivalent impedance of TCSC offers fictitious resistive component leading to mode-detuning. However, it is observed that at higher values of firing angle the resistive behavior diminishes thus resulting in mode-tuning.