Fuzzy logic based SSSC as sub-synchronous resonance damping controller

Abstract

Series capacitive compensation causes sub-synchronous resonance (SSR) problems which results from the interaction between an electrical mode of the series compensated network and the mechanical shaft mode of a turbine generator group. This leads to the turbine generator shaft failure and electrical instability at oscillation frequencies lower than the normal system frequency. In this paper a fuzzy logic control (FLC) is proposed for static synchronous series compensator (SSSC) for damping the oscillations caused by SSR. The performance of the controller has been analysed using IEEE benchmark model to study the sub-synchronous resonance characteristics and to mitigate the problems caused by the SSR using a FLC along with FACTS device (here SSSC is used). The study in this paper is particularly based on the torque amplification after a fault takes place on a series-compensated power system. The Matlab/Simulink program is used for analysis and simulation.