SUBSYNCHRONOUS TORSIONAL OSCILLATIONS AND RESONANCE MITIGATION IN HVDC SYSTEM AND STATCOM COMBINATION

This paper demonstrates the ability of HVDC system and STATCOM as a member of FACTS device to mitigate the unfavorable Subsynchronous Torsional Oscillations (SSTO) and Subsynchronous Resonance (SSR). Two auxiliary controllers are designed and granted to the conventional controllers of each device. It is the first time that the capability of damping controllers are clarified for both SSR and SSTO. Fast Fourier Transform is implemented to analyze the results. Time domain simulation in Matlab/Simulink is carried out on IEEE Second Benchmark Model (SBM) aggregated with HVDC system and STATCOM to prove the effectiveness of the proposed controllers. A comparison between HVDC and STATCOM in SSR attenuation is also investigated. The results prove the exceptional performance of both STATCOM and HVDC when they operate cooperatively.