Single-shaft combined cycle plant control device and single-shaft combined cycle plant control method

A single-shaft combined cycle plant control device for controlling a single-shaft combined cycle plant in which a gas turbine connected to a generator and a steam turbine drivable by steam generated using exhaust heat of the gas turbine are connectable via a clutch, the single-shaft combined cycle plant control device comprising:

• an output calculation unit configured to calculate a gas turbine output on the basis of a generator output calculated based on measurement results of an output current and an output voltage of the generator;
• a fuel flow rate command value calculation unit configured to calculate a fuel flow rate command value on the basis of the generator output;
• a fuel flow rate control unit configured to control a fuel flow rate supplied to the gas turbine on the basis of the fuel flow rate command value;
• a combustion state parameter calculation unit configured to calculate a combustion state parameter of the gas turbine on the basis of the gas turbine output;
• and
• a combustion state control unit configured to control a combustion state of the gas turbine on the basis of the combustion state parameter,
• wherein, when a steam turbine trip event is detected while the single-shaft combined cycle plant is operated with the clutch in the connected state, the fuel flow rate command value calculation unit maintains the fuel flow rate command value constant for a predetermined period from a time of detection of the steam turbine trip event, and the combustion state parameter calculation unit maintains the combustion state parameter constant for the predetermined period.