Device and method for monitoring and controlling security risk of steam turbine rotor in on-line manner

The invention provides a method for monitoring and controlling security risk of a steam turbine rotor in an on-line manner. The method includes: calculating a fault probability FPi of the steam turbine rotor, monitoring a vibration signal of the steam turbine rotor on line, analyzing a vibration frequency of the rotor on line, monitoring a differential expansion signal of the steam turbine on line, monitoring an eccentric signal of the steam turbine rotor on line, calculating an average maintenance time MTTRi of the rotor, determining a weight coefficient Wi of the rotor fault result, calculating a security risk prioritizing number RPNi of the steam turbine rotor, evaluating security risk grade of the steam turbine rotor, determining a maximum security risk prioritizing number RPNmax of the steam turbine rotor, and recommending risk control measures of the steam turbine rotor. The invention provides an on-line monitoring and controlling method of the security risk of the steam turbine rotor, and realizes on-line calculation and control of the security risk of the steam turbine rotor.