Abstract: In one embodiment, a plant control apparatus includes a first stop controller configured to, when stopping a plant, stop a steam turbine to start to drop rotating speed of a second shaft of the steam turbine from rated speed, and start to drop rotating speed of a first shaft of a gas turbine from the rated speed while continuing combustion of a combustor after the stop of the steam turbine. The apparatus further includes a second stop controller configured to shut off fuel of the combustor to stop the gas turbine when the rotating speed of the first shaft drops to first speed. The second stop controller stops the gas turbine such that the rotating speed of the first shaft catches up with the rotating speed of the second shaft at second speed that is equal to or lower than the first speed and a clutch is engaged.

Abstract: In one embodiment, a plant control apparatus includes a first stop controller configured to, when stopping a plant, stop a steam turbine to start to drop rotating speed of a second shaft of the steam turbine from rated speed, and start to drop rotating speed of a first shaft of a gas turbine from the rated speed while continuing combustion of a combustor after the stop of the steam turbine. The apparatus further includes a second stop controller configured to shut off fuel of the combustor to stop the gas turbine when the rotating speed of the first shaft drops to first speed. The second stop controller stops the gas turbine such that the rotating speed of the first shaft catches up with the rotating speed of the second shaft at second speed that is equal to or lower than the first speed and a clutch is engaged.

Abstract: In one embodiment, a plant control apparatus controls a power plant that includes a combustor to burn fuel with oxygen introduced from an inlet guide vane to generate gas, a gas turbine driven by the gas from the combustor, a heat recovery steam generator to generate steam using heat of an exhaust gas from the gas turbine, and a steam turbine driven by the steam from the heat recovery steam generator. The apparatus controls an angle of the inlet guide vane before a start of the steam turbine to a first angle, controls the angle of the inlet guide vane after the start of the steam turbine to a second angle larger than the first angle, and reduce the angle of the inlet guide vane from the second angle to the first angle or more during the predetermined period.

Abstract: In one embodiment, a plant control apparatus controls a power plant that includes a combustor to burn fuel with oxygen introduced from an inlet guide vane to generate gas, a gas turbine driven by the gas from the combustor, a heat recovery steam generator to generate steam using heat of an exhaust gas from the gas turbine, and a steam turbine driven by the steam from the heat recovery steam generator. The apparatus controls an angle of the inlet guide vane before a start of the steam turbine to a first angle, controls the angle of the inlet guide vane after the start of the steam turbine to a second angle larger than the first angle, and reduce the angle of the inlet guide vane from the second angle to the first angle or more during the predetermined period.