Sensitivity and Robustness Analysis for Construction and Monitoring of Tubine-Generator Shafts

Sensitivity and robustness analysis are important tools in order to guarantee an efficient construction and error free running of a turbine generator shaft. It is very important to test different design parameters simultaneously before the machine is in use. Therefore, the knowledge of the characteristic frequencies of the system is crucial since they should be sufficiently different from the excitation frequency, e.g. the electrical main frequency. Often the important system parameters are inexactly or hardly known and so the resulting model, which describes the dynamical behaviour of a turbine generator shaft, differs significantly from reality. Therefore one has to analyze how large the permissible errors in the critical design parameters are, so that a smooth running of the system is still assured. Besides estimating the influence of parameter variations, one also requires a suitable model adaption based on real measured dynamical system parameters. Such a well-adapted shaft model then is the basis for the monitoring of the machine during its life-time.