Patent ID: 8701420

Claim:
A gas turbine control method, comprising: a first step of analyzing pressure fluctuations or accelerations as to combustors in the gas turbine, at each of a plurality of frequency bands over the whole combustion vibration frequency range of the gas turbine; a second step of grasping characteristics relating to the combustion vibrations in the gas turbine, at each of the frequency bands, on the basis of the analysis results obtained by the first step, as well as, on the basis of status signals including the information data regarding actuating variables comprising airflow rate and pilot ratio, namely the ratio of the pilot fuel flow rate to the total fuel flow rate in the gas turbine, as well as, regarding state variables comprising atmospheric condition variables and load index variables in the gas turbine; a third step of computing adjustment increments regarding at least one of the airflow rate into the combustor and the pilot ratio, and making revisions to the actuating variables comprising the airflow rate and the pilot ratio so that the actuating variables are contrasted with the status signals and the variables are modified against initial design conditions, every moment the level of the combustion vibration exceeds a predetermined control criterion; and a fourth step of issuing orders as to the adjustment increments computed in the third step so as to operate the gas turbine, and judging that an unstable phenomenon has disappeared when the level of the combustion vibration is restrained below the predetermined control criterion for a predetermined time span; wherein, on the basis of the judgment result in the fourth step, the gas turbine is operated under the conditions that the revisions according to the third step are reset; and the gas turbine is operated under the control settings of the initial design stage.