Coordinated fuel-air controller for gas turbine without load feedback

摘要

A method of minimizing undesirable emissions from and acoustic pressure oscillations in a gas turbine includes the step of coordinating modulation of turbine fuel and air supply signals to maintain the fuel air ratio (FAR) within a selected range. Coordination of the modulation of fuel and air supply signals includes the steps of producing a turbine fuel supply control signal in correspondence with a turbine speed error signal, generating a coordinated turbine exhaust temperature error signal by modifying a preliminary turbine exhaust temperature error signal in correspondence with the derivative of the speed error signal, and producing a turbine air supply control signal from the coordinated turbine exhaust temperature error signal; the coordinated turbine exhaust temperature error signal provides coordination between the turbine fuel supply signal and the turbine air supply signal so as to maintain the fuel-air ratio of the combustible mixture being fed to the turbine within the selected range.