Subsynchronous torsional interactions with static VAR compensators-influence of HVDC

Planning for the installation of a static VAR compensator (SVC) in Chester, Maine, was initiated in 1987. The prespecification subsynchronous torsional interaction (SSTI) studies showed that the SVC might have a negative influence on the stability of torsional modes of vibration of the nearby turbine generators. The parameters influencing the level of SSTI have previously been identified by the authors by using a simple system (1989). This work is extended to power systems containing an HVDC transmission system. The combined effect of SVC and HVDC on turbine-generator SSTI is investigated with the use of a hypothetical system. Simulation plots for the large machines of New Brunswick and Maine are included to quantify the level of interaction with the Chester SVC. Filtering as a mitigation measure is proposed to eliminate the small level of SSTI attributed to the Chester SVC.<
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