Valve control device, gas turbine, and valve control method

A valve control device provided in a gas turbine, the gas turbine comprising:

• a combustor for generating combustion gas by combusting fuel;
• a turbine driven by the combustion gas generated by the combustor;
• a flow rate regulating valve for regulating a flow rate of the fuel to be supplied to the combustor;
• and a pressure regulating valve disposed upstream of the flow rate regulating valve in a fuel passage for supplying the fuel to the combustor, for regulating the fuel pressure,
• wherein the valve control device controls at least opening degree of the pressure regulating valve,
• the valve control device comprising:
• a detection section for detecting a load decrease of the gas turbine;
• and
• a pressure control section for controlling the opening degree of the pressure regulating valve on the basis of an output value of the gas turbine after the load decreases when the detection section detects the load decrease.