Grid induced torsional vibrations in turbine-generators — Instrumentation, monitoring, and protection

Six areas of focus for turbine-generator torsional vibration monitoring are discussed: 1) The value case for generator torsional vibration monitoring, 2) Environmental factors leading to vibration exposure, 3) Experience with torsional monitoring and protection, 4) Monitoring and Protection system design, 5) Evaluating response, stress and fatigue, and 6) the case for standards of turbine-design for torsional withstand. It is concluded that more work is needed on standards for turbine-generator capability for off-nominal operation. That the art of torsional monitoring and protection is well advanced and can be profitably fostered by owners of turbine-generators given the state of the standards, the environment factors, and the margins for operation.