Turbine-Generator Impact Torques in Routine and Fault Operations

This paper reviews the shaft impact loadings created in turbine-generator shafts by both normal and fault initiated switching sequences. Its objectives are to clarify the significance of shaft impact torque simulations in relation to shaft fatigue life data and to indicate the practicality of handling impact loading questions in the course of normal transient stability calculations. Examples presented in this paper compare shaft impacts produced by unit tripping, single and three-phase faults, high-speed reclosing, and manually timed switching sequences.