PROTECTING METHOD AND PROTECTING DEVICE FOR SHAFT SYSTEM TORSIONAL VIBRATION OF STEAM TURBINE GENERATOR UNIT

摘要

A protecting method and protecting device for shaft system torsional vibration of a steam turbine generator unit. By acquiring a shaft system torsional vibration signal and applying a fatigue inverse time limit criterion (protection criterion I), a static instability criterion (protection criterion II) and a quick action criterion (protection criterion III) to determine the conditions of torsional vibration threatening the safety of a unit, protection trip and warning are performed, thereby avoiding greater damage of the torsional vibration to a shaft system of the generator unit. The protecting device for torsional vibration comprises a speed sensor, a pulsed quantity input module (PI), a main control module (CM), a digital quantity input module (DI), an analog quantity input module (AI), a digital quantity output module (DO) and a power supply module (POW). The speed sensor is connected to the pulsed quantity input module of the protecting device by means of a cable; and the protecting device externally communicates with a human-machine interface (HMI) of a main station via Ethernet.