A Subsynchronous Resonance Suppression Method by Transient Current Filtering Based on STATCOM

Subsynchronous resonance includes inductive generator effect, torsional interaction and transient torque amplification. The mainstream method to suppress torsional interaction in series compensated transmission systems is improving the damping of the system based on power electronic equipment. In contrast, there is currently no good ways to cope with transient torque caused by violent disturbances. This paper proposes a transient current filtering method based on static synchronous compensator to suppress the transient torque amplification. This method can significantly reduce the impact on the shaft system by filtering out the transient component of the stator current when system occurs a large disturbance, thereby suppressing the modal oscillation. Based on the IEEE first benchmark model (FBM), this paper lists the differential equations of electromechanical coupling system, and illustrates the impact of this method on the system oscillation characteristics through the eigenvalue analysis. Finally, effectiveness for the method is verified through PSCAD/EMTDC time domain simulation.