Design of a robust SSSC supplementary controller to suppress the SSR in the series-compensated system

This paper presents the design of an H-infinity based robust Static Synchronous Series Compensator (SSSC) supplementary controller to suppress the subsynchronous resonance (SSR) in the series-compensated system. The modified IEEE second benchmark, System-1 model is employed for this study. In order to design the effective controller, the modal observability to the oscillation modes is considered. Comprehensive time domain simulation studies using the nonlinear system model show that the proposed H-infinity SSSC supplementary controller can suppress the SSR efficiently in spite of the variations of power system operating conditions.