Torsional Vibration and Fatigue of Turbine-Generator shafts

Transmission system events and operations which have the potential for removing significant fatigue life fram turbine-generator shafts are described. The factors which limit the fatigue capability of turbine-generator shaft systems are presented, along with a discussion of analytical models and their limitations for estimating the shaft fatigue duty following a defined electrical disturbance. The basis for a screening guide value for planned switching operations presented to the IEEE Working Group studying the effects of high speed switching is also discussed.