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. The plant includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam by using heat of exhaust gas from the gas turbine, a first steam turbine driven by the first steam, a reheater provided in the boiler and configured to heat exhaust steam from the first steam turbine by the exhaust gas to generate reheat steam, and a second steam turbine driven by the reheat steam. The apparatus includes a first warming-up module to supply second steam from equipment different from the boiler to the first steam turbine to warm up this turbine, before this turbine is started. The apparatus further includes a second warming-up module to supply the second steam to the reheater to warm up the reheater, before the first steam turbine is started.

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, which includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam using heat of exhaust gas from the gas turbine, a steam turbine driven by the first steam, and a clutch to connect a first shaft connected to the gas turbine and generator with a second shaft connected to the steam turbine. The apparatus includes a starting module to start the gas turbine and generator while holding the steam turbine in a stop state, when the clutch is in a released state. The apparatus further includes a warming module to warm the steam turbine by supplying second steam from equipment different from the boiler to the steam turbine in parallel with the starting of the gas turbine and generator, when the clutch is in a released state.

Abstract: In one embodiment, a plant control apparatus controls a power plant, which includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam using heat of exhaust gas from the gas turbine, a steam turbine driven by the first steam, and a clutch to connect a first shaft connected to the gas turbine and generator with a second shaft connected to the steam turbine. The apparatus includes a starting module to start the gas turbine and generator while holding the steam turbine in a stop state, when the clutch is in a released state. The apparatus further includes a warming module to warm the steam turbine by supplying second steam from equipment different from the boiler to the steam turbine in parallel with the starting of the gas turbine and generator, when the clutch is in a released state.

Abstract: In one embodiment, a plant control apparatus controls a power plant. The plant includes a gas turbine, a generator driven by the gas turbine, an exhaust heat recovering boiler to generate first steam by using heat of exhaust gas from the gas turbine, a first steam turbine driven by the first steam, a reheater provided in the boiler and configured to heat exhaust steam from the first steam turbine by the exhaust gas to generate reheat steam, and a second steam turbine driven by the reheat steam. The apparatus includes a first warming-up module to supply second steam from equipment different from the boiler to the first steam turbine to warm up this turbine, before this turbine is started. The apparatus further includes a second warming-up module to supply the second steam to the reheater to warm up the reheater, before the first steam turbine is started.