Gas turbine control method and device

A gas turbine control system for controlling a gas turbine plant and a gas turbine thereof, the system comprising:

• a process variables detecting unit having a vibration measuring unit that measures combustion vibrations occurring in each combustor of the gas turbine as pressure fluctuations or accelerations, a fuel property measuring unit that measures components or calorific value of fuel supplied to the combustor, and a process variables measuring unit that measures the process variables regarding fuel and air supplied to the combustors, the process variables detecting unit being configured to detect a plurality of process variables including process variables regarding fuel and air supplied to the combustor, which affect the combustion vibrations;
• a combustion characteristic grasping unit that establishes mathematical models by mathematically-modeling information regarding the components or the calorific value of the fuel, flow rate of the air, and the process variables as independent variables, on a basis of a vibration level analyzed for each vibration frequency bandwidth based on the plurality of the process variables detected by the process variables detecting unit, the information regarding the components or the calorific value of the fuel measured by the fuel property measuring unit, and the pressure fluctuations or the accelerations obtained by the vibration measuring unit;
• a countermeasure decision unit that increases and decreases flow rate of fuel or air supplied to the combustor so as to maintain an operation condition under which the combustion vibrations are unlikely to occur based on the mathematically-modeled combustion vibration characteristics;
• and
• a plurality of databases into which said process variables of the gas turbine is divided and stored in response to the detected values of the components or the calorific value of the fuel;
• wherein said process variables are divided and stored into the plurality of databases such that adjacent databases have a common interval which is an area a boundary region of each of the adjacent databases having data regarding the components or the calorific value overlaps;
• and
• a threshold value in a part of the common interval is set;
• and
• said combustion characteristic grasping unit retrieves the detected values of the components or the calorific value of the fuel from the plurality of databases with the detected values of the other process variables, and performs approximation treatments of the combustion vibration characteristics based on the retrieved values;
• wherein, regarding the data in the common interval of the adjacent databases, said combustion characteristic grasping means retrieves data from the common interval of either one of the adjacent databases of which are detected values of the components or the calorific value of the fuel are continuous, and performs the approximation treatments on the retrieved data.