THE TORSIONAL VIBRATION OF STEAM TURBO-GENERATOR SHAFT SYSTEM TAKING INTO ACCOUNT TEMPERATURE DISTRIBUTION AND STEAM FLOWING

摘要

The turbine-generator shafts may be damaged by torsional vibration or by subsynchronous resonance (SSR) when the load disturbances occur as a result of the disturbances from control system, generator, or electric network. Many people have been doing researches on the torsional vibration of turbo-generator shaft system. Most previous studies thought that the shear modulus of a shaft can be regarded as a constant and the process of steam flowing in turbine can be ignored. In fact, the shear modulus changes with the change of the material's temperature, and steam flowing can not be ignored although the time of the process is very short. This paper builds the models of the shaft system and the control system, analyses the torsional vibration characteristics and the torsional responses of turbo-generator set taking into account temperature distribution and steam flowing. The continuum transfer matrix method is used and a 300MW steam turbo-generator set is given as a example.