Damping of sub-synchronous resonance and low-frequency power oscillation in a series-compensated transmission line using gate-controlled series capacitor

In this paper, the impact of different gate-controlled series capacitor (GCSC) control methodologies on sub-synchronous resonance (SSR) problems of series capacitive compensated transmission lines is analyzed. The low-frequency power oscillation (LFPO) damping using GCSC also is studied. In these studies, the effect of the rating of the GCSC is also considered. Three different control methodologies are proposed: open loop, constant power, and Takagi-Sugeno (TS) fuzzy control. It is shown that the GCSC can damp both the SSR and LFPO using the constant power control (CPC) methodology. It is also shown that when the parameters of the CPC is optimized by the TS fuzzy controller, the third methodology can present a cost-effective solution for both the SSR and LFPO damping. In this work, the IEEE First Benchmark Model is employed, including a GCSC device, and the study is performed using MATLAB program.