A method of bowed rotor start response damping for a gas turbine engine is provided. A spring rate and a damping characteristic of one or more bearing supports in the gas turbine engine are selectively modified while a shaft of the gas turbine engine rotates below a speed which is adversely affected by a bowed rotor condition of the gas turbine engine.

A bowed rotor start mitigation system for a gas turbine engine of an aircraft is provided. The bowed rotor start mitigation system includes a motoring system and a controller coupled to the motoring system and an aircraft communication bus. The controller is configured to determine at least one inferred engine operating thermal parameter from at least one aircraft-based parameter received on the aircraft communication bus. The motoring system is controlled to drive rotation of a starting spool of the gas turbine engine below an engine idle speed based on determining that the at least one inferred engine operating thermal parameter is within a preselected threshold.

A bowed rotor start mitigation system for a gas turbine engine is provided. The bowed rotor start mitigation system includes a variable position starter valve and a controller. The controller is operable to dynamically adjust the variable position starter valve to deliver a starter air supply to a starter to drive rotation of a starting spool of the gas turbine engine according to a dry motoring profile that continuously varies a rotor speed of the starting spool up to a point below a critical rotor speed.

An engine starting system for a gas turbine engine is provided. The engine starting system comprising: a gas turbine engine including rotational components comprising an engine compressor, an engine turbine, and a rotor shaft operably connecting the engine turbine to the engine compressor, wherein each rotational component is configured to rotate when any one of the rotational components is rotated; a permanent magnet alternator operably connected to at least one of the rotational components, the permanent magnet alternator being configured to rotate the rotational components; and a motor controller in electronic communication with the permanent magnet alternator, the motor controller being configured to command the permanent magnet alternator to rotate the rotational components at a selected angular velocity for a selected period of time.

An engine starting system for a gas turbine engine is provided, the engine starting system comprising: a gas turbine engine including rotational components comprising an engine compressor, an engine turbine, and a rotor shaft operably connecting the engine turbine to the engine compressor, wherein each rotational component is configured to rotate when any one of the rotational components is rotated; an electro-pneumatic starter operably connected to at least one of the rotational components, the electro-pneumatic starter being configured to rotate the rotational components; an electric drive motor operably connected to the electro-pneumatic starter, the electric drive motor being configured to rotate the rotational components through the electro-pneumatic starter; and a motor controller in electronic communication with the electric drive motor, the motor controller being configured to command the electric drive motor to rotate the rotational components at a selected angular velocity for a selected period of time.

A bowed rotor start mitigation system for a gas turbine engine is provided. The bow rotor start mitigation system includes a controller operable to receive a speed input indicative of a rotor speed of the gas turbine engine and a measured temperature of the gas turbine engine. The controller is further operable to drive motoring of the gas turbine engine by oscillating the rotor speed within a motoring band for a motoring time based on the measured temperature when a start sequence of the gas turbine engine is initiated.

An electric machine and a turning gear system for aircraft gas turbine engines are provided. The system has an electric machine designed for dual mode operation and a controller. The stator winding arrangement in the electric machine enables operation in either generating mode, during normal flight or motoring mode, during active engine turning. The controller is configured to reconfiguration connections of the windings external to the electric machine.

Embodiments of the disclosure provide a method for controlling steam pressure within a turbine component. The method includes calculating a predicted stress on a rotor of the turbine component based on a predicted steam flow with the inlet valve in a minimum load position, a rotor surface temperature, and an inlet steam temperature, and determining whether the predicted stress exceeds a threshold. If the predicted stress exceeds the threshold, the inlet valve adjusts to a warming position. When steam in the discharge passage reaches a target pressure, the exhaust valve partially closes while maintaining the warming position of the inlet valve. If a safety parameter of the turbine component violates a boundary, the exhaust valve partially opens while maintaining the warming position of the inlet valve. When the predicted stress does not exceed the threshold, the inlet valve opens to at least the minimum load position.

Embodiments of the disclosure provide a method for controlling steam pressure within a turbine component. The method includes calculating a predicted stress on a rotor of the turbine component based on a predicted steam flow with the inlet valve in a minimum load position, a rotor surface temperature, and an inlet steam temperature, and determining whether the predicted stress exceeds a threshold. If the predicted stress exceeds the threshold, the inlet valve adjusts to a warming position. When steam in the discharge passage reaches a target pressure, the exhaust valve partially closes while maintaining the warming position of the inlet valve. If a safety parameter of the turbine component violates a boundary, the exhaust valve partially opens while maintaining the warming position of the inlet valve. When the predicted stress does not exceed the threshold, the inlet valve opens to at least the minimum load position.

Provided is a steam turbine plant activation control device that can flexibly handle an initial state amount of a steam turbine plant and activate a steam turbine at a high speed. The activation control device 21 for the steam turbine plant includes a heat source device 1 configured to heat a low-temperature fluid using a heat source medium and generate a high-temperature fluid, a steam generator 2 for generating steam by thermal exchange with the high-temperature fluid, a steam turbine 3 to be driven by the steam, and adjusters 11, 12, 13, 14, 15 configured to adjust operation amounts of the plant.