Damping subsynchronous resonance using a STATCOM operating in a phase imbalanced mode

This paper describes the potential usage of a STATCOM installed in the power system for damping torsional oscillations induced in turbine generators in series capacitive compensated transmission grids. This is achieved by operating the STATCOM in a phase imbalanced mode for a few seconds after a large system disturbance. The phase imbalanced operation reduces the energy exchange between the electrical and mechanical sides of the turbine generator and, therefore, damps the subsynchronous torsional oscillations resulting from series capacitive compensation. The validity and effectiveness of the proposed scheme is demonstrated using the IEEE first benchmark model for computer simulation of subsynchronous resonance by means of time domain simulation analysis using the EMTP-RV program.