The Torsional Stress Analyzer for Continuously Monitoring Turbine-Generators

The paper describes the Torsional Stress Analyzer´ that is designed to monitor the mechanical impact of all electrical disturbances on a turbine-generator. The operating principle is explained, and the components of the TSA system related to processing the input values and electronic torsional simulation of the turbine-generator shaft are presented. Explanations are given as to how the effect of any disturbance is evaluated in terms of inflicted turbine-generator shaft torsional fatigue, coupling deformation and generator stator end winding stressing. Practical usage and simple interpretation of the TSA process computer output data are provided. The factory calibration procedures and tests, as well as the built-in tests are outlined. Oscillograms of shaft torque outputs from a TSA recorded during an actual switching operation are compared with those obtained from the standard TSA factory tests. The results of tests to compare shaft torques simulated by TSA equipment with those measured by strain gauges are presented. The short and long-term benefits of applying TSA systems to large steam turbine-generators are discussed.