The present application relates to a method and device of turbine-generator shaft torsional vibration protection. By acquiring shaft torsional vibration signal and applying three criteria: fatigue inverse time limit criterion, static instability criterion and fast action criterion, the device can issue trip and/or alarm signals when the torsional vibration threatens shaft safety, so as to avoid more damage to the turbine-generator shaft system. Modal filtering of pulse inputs are used to obtain angular speed variations of the shaft ends at individual modes. Oscillating components of individual torsional vibration modes and amplitude of each sub-synchronous mode signal are acquired. The torsional vibration protection device includes: speed sensors, pulse input module (PI), control module (CM), digital input module (DI), analog input module (AI), digital output module (DO) and power supply module (POW). The speed sensors are connected with the PI module by cable. The torsional vibration protection device communicates with human machine interface (HMI) of main station by Ethernet.
Turbine-generator shaft torsional vibration protection method and device