Single-Phase VSC Based SSSC for Subsynchronous Resonance Damping

In this paper, a novel control strategy for subsynchronous resonance (SSR) mitigation using a static synchronous series compensator (SSSC) will be presented. The SSSC is constituted by three single-phase voltage source converters. SSR mitigation is obtained by increasing the network damping only at those frequencies that are critical for the turbine-generator shaft. This is achieved by controlling the subsynchronous component of the grid current to zero. Using the IEEE First benchmark model, the effectiveness of the proposed control algorithm when mitigating SSR due to torsional interaction and torque amplification effect will be shown.