Damping of subsynchronous oscillations in power system using static synchronous series compensator

Abstract

In this study, a static synchronous series compensator (SSSC) is used to damp the subsynchronous oscillation in a power system compensated by the series capacitor. In order to achieve an effective damping, a supplementary subsynchronous damping controller (SSDC) is added to the SSSC. The only input signal for the SSDC is the rotor speed deviation to generate the modulation index for controlling the injected voltage of the voltage-sourced converter (VSC). Also, the chaotic optimisation algorithm is employed to tune the parameter of SSDC. The design objective is to suppress the subsynchronous resonance (SSR) caused by the series capacitor. By using the SSDC, the SSSC connected at the transmission line is able to damp the SSR. The first system of IEEE second benchmark model is used to evaluate the effective of SSDC on the torsional oscillations. The several simulations are used to demonstrate the ability of SSDC in damping the SSR.