Damping subsynchronous oscillation by static VAR compensator

Because of large-capacity, long-distance and cross-region power transmission in our country´s power grid, the subsynchronous oscillation (SSO) will arise from the use of series capacitor compensation and HVDC. Damping subsynchronous oscillation using static VAR compensators (SVC) is investigated in this paper. In order to damp the various unstable torsional modes, a subsynchronous damping controller is designed according to the phase compensation methods. Eigenvalue analysis of the closed-loop system and test signal method reveal that this controller is quite effective. The time domain simulations are also performed to demonstrate the effectiveness of the proposed controller under disturbance condition.