Electrical Damping and its Effect on Accumulate Fatigue Life Expenditure of Turbine-Generator Shafts Following Worst-Case Supply System Disturbances

Abstract
The paper examines the effect electrical phenomena has on damping torsional vibrations of turbine-generator shafts resulting from severe disturbances on the system supply. The effect system impedance and power factor has on time constants for decay of predominant shaft torsional vibrations and on fatigue life expenditure of the shaft following worstcase events is investigated. The impact pole slipping resulting from delayed fault clearance has on peak shaft torque and on accumulative fatigue life expenditure of the shaft is also examined.