The suppression of slightly damped torsional oscillations in autonomous power systems

The countermeasures for suppression of slightly damped vibrations caused first critical frequency of gas turbine torsional oscillations are considered as a consequence of interaction with power electronics consumers in oil-field autonomous power system. It is shown that torsional oscillations damping could be achieved by using existing reactive power source, which consists of controlled shunt reactor (CSR) and capacitor banks as well as additional active RLC-filter enhanced by auxiliary control loops of shaft torque and it's first and second derivative in both cases. The procedure for coordinated tuning of selectable system regulators (PSS, CSR, Alter, etc.), based on multi-parameter numerical optimization, is given to improve torsional oscillation damping.