Analysis of Sub Synchronous Resonance and its Effects on EHV/UHV Transmission Systems

This paper illustrates the effect of Thyristor controlled series capacitor (TCSC) structures and synchronization response on sub synchronous damping. In spite of various studies concerning sub synchronous behavior of TCSC, effect of these factors on sub synchronous damping are rarely discussed. Studies have been executed using PSCAD transient simulation programme with general power system and TCSC simulation models. It has considered the application of TCSC for closed-loop control of power flow in both constant power and constant angle models of operation. These results indicate that the power flow controller (TCSC) operation has an important influence on both the small signal and transient stability characteristic of the system.