Apparatus for estimating the strain on an inaccessible portion of a rotating shaft

摘要

This invention concerns apparatus for reliably estimating the strain on an inaccessible portion of a shaft of a turbine generator system which is susceptible to torsional oscillation. The strain is continuously predicted on a real time basis as a function of the modal analysis parameters of the shaft. Furthermore, system torque is detected electrically at the output of the generator. This signal along with signals representative of shaft angular velocity at the easily accessible ends thereof is provided to the modal analysis means as inputs. The provision of these latter system data allow for the elimination of an equal number of unknowns in the modal analysis representation, thus reducing the complexity of the analyzing system and increasing the reliability.