Abstract: A gas turbine engine including a first shaft being one of a main shaft concentrically mounted to at least one turbine rotor and a tower shaft directly driven by the main shaft and extending generally radially therefrom, the first shaft having a reduced diameter portion located within the gas turbine engine, an electrical assembly having a rotor comprising permanent magnets retained on an outer surface of the reduced diameter portion and a stator comprising a magnetic field circuit disposed adjacent an outer periphery of the rotor, and an electrical connection between the magnetic field circuit and at least one of a power source and an electrically drivable accessory.

Abstract: Control systems and a method for controlling a load point of a gas turbine engine are provided. A control system includes a controller that receives a temperature signal and a pressure signal associated with exhaust gases from the gas turbine engine. The controller is further configured to generate the fuel control signal. The controller is further configured to generate an actuator control signal such that flow restriction member is moved from the first operational position to the second operational position to restrict the flow path such that the exhaust gases have a temperature level within a desired turndown temperature range, the pressure level in the exhaust gases is less than a threshold pressure level, and the load point of the gas turbine engine is adjusted to toward a target load point.

Abstract: The invention relates to a combination power plant which is embodied as a single shaft, power plant, essentially consisting of a gas turbine, a steam turbine and a generator which is connected therebetween. A coupling is arranged between the generator and the steam turbine, and at least one drive device, which is used to drive the single-shaft power plant, is also provided. The coupling is uncoupled during a turning operation and a control unit, which is used to control the rotational speed of the steam turbine, is provided.

Abstract: A method for controlling a gas turbine including a compressor assembly including at least one variable geometry portion, a combustion chamber, and a turbine assembly. The method generates a flow rate setpoint value for fuel to be fed to the combustion chamber as a function of a desired speed of the gas turbine, computes threshold values for maintaining the fuel flow setpoint value in a given range, the threshold values depending on a thermodynamic state of the gas turbine, and controls the position of the variable geometry portion by controlling an actuator as a function of the difference between position information representative of the instantaneous position and setpoint position information. The threshold values are automatically adjusted by computation in real time as a function of the instantaneous position information of the variable geometry portion or of the difference between this position information and the setpoint position information.

Abstract: Systems and methods may be provided for exhaust gas recirculation. The systems and methods may include receiving, via an intake section, inlet air at an input of a compressor, generating compressed air at the compressor using the received inlet air, and providing the compressed air from the compressor to a combustor, where the combustor produces combustion involving the compressed air and fuel. The systems and methods may also include receiving combustion products associated with the combustion at a turbine component, where the turbine component releases exhaust gases, and recirculating at least a portion of the exhaust gases to the intake section via a recirculation line, where the recirculated exhaust gases raise a temperature of the inlet air.

Abstract: A turbine engine assembly for a generator including a turbine engine having a compressor section, a combustor section and a turbine section, and the turbine engine having a base load. The combustor section includes a combustor and a combustor shell. A flow control device is located in a flow path between the combustor shell and an inlet to the combustor. The flow control device effects an increase in a pressure drop of shell air flowing from the combustor shell to the combustor. A controller is provided for operating the flow control device to change a pressure drop across the flow control device, wherein an increase in the pressure drop across the flow control device results in a corresponding reduction in mass flow through the combustor for effecting a reduction in power output from the turbine engine during a reduction in an operating load to less than the base load.

Abstract: Tuning processes implemented by an auto-tune controller are provided for measuring and adjusting the combustion dynamics and the emission composition of a gas turbine (GT) engine via a tuning process. Initially, the tuning process includes monitoring parameters, such as combustion dynamics and emission composition. Upon determining that one or more of the monitored parameters exceed a critical value, these “out-of-tune” parameters are compared to a scanning order table. Upon comparison, the first out-of-tune parameter that is matched within the scanning order table is addressed. The first out-of-tune parameter is then plotted as overlaid slopes on respective graphs, where the graph represents a fuel-flow split. Typically, the slopes are plotted as a particular out-of-tune parameter against a particular fuel-flow split. The slopes for each graph are considered together by taking into account the combined impact on each out-of-tune parameter when a fuel-flow split is selected for adjustment.

Abstract: A method and system for controlling an exhaust gas recirculation (EGR) system is provided. The method and system may incorporate a device or devices that continuously monitors an exhaust stream for harmful constituents. The method and system may control components of the EGR system based on the concentration of harmful constituents within the exhaust.

Abstract: Methods and systems for mitigating distortion of a shaft of a gas turbine engine are provided. One method comprises at least one step of applying intermittent rotary power to a shaft of a gas turbine engine. The step of applying intermittent power to the shaft is performed during a period where conditions of temperature differential in the engine exist capable of distorting the shaft. The methods and systems shorten the time needed to start a gas turbine engine in such a way that bowing of a shaft is not a significant problem.

Abstract: A method is provided for operation of an integrated solar combined-cycle power station. The power station includes a water/steam circuit having a steam turbine and a heat recovery steam generator through which hot exhaust gases from a gas turbine flow. The water/steam circuit is additionally supplied with heat from a solar array. In such a method, an optimum cost-benefit relationship is achieved in that the water/steam circuit is designed only for the full load on the gas turbine, and in that, when feeding additional power from the solar array into the water/steam circuit, the load on the gas turbine is reduced, on the basis of the power additionally fed in from the solar array, to such an extent that the total output power of the integrated solar combined-cycle power station remains substantially constant.

Abstract: A combustion system for a gas turbine engine is provided. The system includes a forward liner; an aft liner; a combustion chamber formed by the forward liner and the aft liner, the combustion chamber defining a lean combustion zone and a pilot combustion zone; a premixing zone coupled to the combustion chamber; a pilot fuel injector coupled to the combustion chamber and configured to deliver a first flow of fuel to the pilot combustion zone; and a slinger unit configured to deliver a second flow of fuel to the premixing zone such that the second flow of fuel is mixed with air in the premixing zone and directed into the lean combustion zone of the combustion chamber.

Abstract: A gas turbine compressor (28A, 28B) sized to support respective maximum design points of other gas turbine driven electrical power generating system components (30, 32, 38, 46, 58, 68) during a least dense ambient condition within a design range of ambient conditions. A variable inlet (72) on the compressor automatically modulates to modulate airflow to supply just the amount needed to produce a rated output of the system throughout the full design range of ambient conditions. This safely and economically maintains rated power system output (94) over a full range of ambient conditions.

Abstract: Disclosed are a control method and a control device for an exhaust heat recovery system which are capable of preventing an onboard supply power outage in response to a sharp change in the load of the main drive machine.

Abstract: An improved inlet bleed heat system for a gas turbine engine is disclosed. The inlet bleed heat system provides improved mixing in an inlet region while permitting the engine to be operated at lower power settings. The inlet bleed heat system comprises a supply conduit, a plurality of feed tubes extending from the supply conduit, and a guide tube for receiving opposing ends of the feed tubes. The plurality of feed tubes each have a plurality of injection orifices and the feed tubes are oriented such that the injection orifices generally face into a flow of oncoming air with the feed tubes being positioned forward of a plurality of sound attenuating baffles.

Abstract: A gas turbine and method are disclosed by which the gas turbine can be safely operated at nominal speed with reduced margin to a surge limit of a compressor. The gas turbine, via a directly driven generator which generates alternating current with an operating frequency and which is connected in a frequency-coupled manner to an electricity grid, can deliver electric power to this grid. In the case of an underfrequency event the compressor of the gas turbine is unloaded by controlled, fast closing of the variable compressor guide vanes (VGV) and as a result maintains a sufficient margin to the surge limit of the compressor.

Abstract: A gas delivery system includes a gas booster module for delivering natural gas from a utility gas service to power generation equipment installed in or around a building in a manner that meets the minimum volume and pressure requirements of the power generation equipment. The gas delivery system advantageously uses pipe of a relatively small size for delivering gas to the power generation equipment, thereby substantially reducing installation costs and eliminating the need for a welded gas line. The gas delivery system also provides a control system that facilitates close control over the gas flow and ensures compliance with local building codes and safety regulations and requirements.

Abstract: A method and controller for identifying lean blowout conditions in a Dry Low NOx (DLN) combustor during a premix mode. An effective approach to quickly and reliably identify a blowout during operation in the premix mode is by the effect on fuel normalized power (FNP). FNP is a useful signal, in that a power reduction from a blowout may be distinguished much slower changes in power resulting from global fuel demand (changing load request). A difference between the FNP and a filtered FNP parameter may be compared against a predetermined threshold. If the difference exceeds the threshold, a lean blowout is identified and a signal may be transmitted to the turbine controller to reposition combustor operation away from blowout conditions.

Abstract: Apparatus for regulating the flow rate of fuel to a turboshaft engine in acceleration or in deceleration, the engine having a free turbine and a core engine, the apparatus comprising sensors transmitting information to regulator means, said information relating: to a first speed of rotation NTL of said free turbine; to a second speed of rotation Ng of said engine's gas generator; to an internal temperature T4 of the gas at the inlet to the free turbine; to the external pressure; and to the external temperature. The apparatus further comprises control means activated by said regulator means to actuate a fuel metering system of the engine. In addition, the regulator means evaluates the flow rate of fuel to be supplied to the engine in acceleration or in deceleration on the basis of at least one optimum regulation relationship, said regulation relationship determining a main modulated flow rate as a function of a modulated speed of rotation.

Abstract: A land based gas turbine apparatus includes an integral compressor; a turbine component having a combustor to which air from the integral compressor and fuel are supplied; and a generator operatively connected to the turbine for generating electricity; wherein hot gas path component parts in the turbine component are cooled entirely or at least partially by cooling air or other cooling media supplied by an external compressor. A method is also provided which includes the steps of supplying compressed air to the combustor from the integral compressor; and supplying at least a portion of the cooling air or other cooling media to the hot gas path parts in the turbine component from an external compressor.

Abstract: A gas turbine engine control system includes a module operable to fail-fix the gas turbine engine to one of a multiple of pre-determined modes in response to failure of an automatic control.

Abstract: A gas turbine engine having an adaptive core capable of maintaining a substantially constant core pressure ratio while having a variable flow rate is disclosed. In one aspect, the adaptive core comprises a front block compressor and a rear block compressor.

Abstract: The present invention provides a gas turbine capable of reducing energy consumption while suppressing a so-called cat back phenomenon. The gas turbine includes a combustor-accommodating chamber casing for accommodating therein a combustor which burns fuel and air compressed by a compressor to generate combustion gas and which injects the combustion gas to a turbine. The gas turbine also includes a first air supply passage and a second air supply passage on an upper portion of the combustor-accommodating chamber casing in the vertical direction. The first air supply passage discharges air toward the compressor in the combustor-accommodating chamber casing. The second air supply passage discharges air in a direction different from that of the first air supply passage.

Abstract: A twin-shaft gas turbine 1, which has a gas generator 2 including a compressor 7, a combustor 8, and a high-pressure turbine 9, is configured to make a first control mode and a second control mode selectively useable for control of the gas generator. In addition, in the first control mode, an IGV angle in the compressor is controlled in accordance with a corrected shaft rotation speed of the gas generator, and in the second control mode, the IGV angle is controlled to maintain a constant gas generator shaft rotation speed. Furthermore, the first control mode is used to start, to stop, and to operate the turbine under fixed or lower load conditions, and that the second control mode is used under operational states other than those to which the first control mode is applied.

Abstract: An inner core cowl baffle assembly for a turbofan engine assembly is provided. The engine assembly includes a core gas turbine engine, a core cowl which circumscribes the core gas turbine engine, a nacelle positioned radially outward from the core cowl, and a fan nozzle duct defined between the core cowl and the nacelle. The inner core cowl baffle assembly includes an inner core cowl baffle, and an actuator assembly configured to vary the throat area of the fan nozzle duct by selectively repositioning the inner core cowl baffle with respect to the core cowl.

Abstract: A fuel controller, and associated method, provides a fuel control output signal to a fuel control actuator to control operations. The fuel controller determines the fuel control output signal based on rotational speed error. A combustion air controller provides a combustion air control output signal to a combustion air control actuator to control operations. A cross channel controller is in communication with the fuel controller and the combustion air controller. The cross channel controller provides a combustion air control modification signal to the combustion air controller. The combustion air control modification signal is determined from the fuel control output signal using an air versus fuel model. The combustion air controller determines a preliminary combustion air control signal based on an exhaust temperature error, and further determines the combustion air control output signal based on both of the preliminary combustion air control signal and the combustion air control modification signal.

Abstract: A system includes a drive shaft, a motor-generator coupled to the drive shaft, a compressor coupled to the drive shaft and configured to output compressed air to a cavern, and a turbine coupled to the drive shaft and configured to receive air from the cavern. The system includes a first thermal energy storage (TES) device, a combustor configured to combust a flammable substance and generate an exhaust stream to the turbine, and controller. The controller is configured to control flow of the air to heat the air as it passes through the first TES, cause the flammable substance to flow to the combustor, operate the combustor to combust the air with the flammable substance to generate an exhaust stream into the turbine, and control the motor-generator to generate electrical energy from energy imparted thereto from the turbine via the drive shaft.

Abstract: A method of operating a gas turbine engine having a rotatable turbine shaft with an electric machine mounted to the shaft. The method includes providing supplemental acceleration and/or deceleration of the turbine shaft of the gas turbine engine through the use of the electric machine operated as an electric motor and/or an electric generator, in order to avoid an undesirable engine speed range during engine operation.

Abstract: A lean blowout protection system and method is provided that facilitates improved lean blowout protection while providing effective control of turbine engine speed. The lean blowout protection system and method selectively and gradually biases the lean blowout (LBO) schedule based on current engine data. This facilitates improved lean blowout protection while providing effective control of turbine engine speed and temperature.

Abstract: The present invention relates to control of engine variable of a gas turbine engine to regulate the surge margins of at least two compressors. A controller (20) receives data measured from engine sensors (22, 23) and uses said data to determine an indication of surge margin for each of at least two compressors (6, 7) of the gas turbine engine. The controller (20) uses the indications of surge margin for each of the compressors to determine a control strategy that balances the requirements of each compressor. In one embodiment a surge margin operating map divided into different control domains (40, 43, 43) is used. The indication of surge margin determined for each compressor is plotted to determine which control domains the current operating point on the surge margin operating map falls within.

Abstract: A method for multi-objective fault accommodation using predictive modeling is disclosed. The method includes using a simulated machine that simulates a faulted actual machine, and using a simulated controller that simulates an actual controller. A multi-objective optimization process is performed, based on specified control settings for the simulated controller and specified operational scenarios for the simulated machine controlled by the simulated controller, to generate a Pareto frontier-based solution space relating performance of the simulated machine to settings of the simulated controller, including adjustment to the operational scenarios to represent a fault condition of the simulated machine.

Abstract: A gas turbine engine control system comprises a data acquisition and analysis system for receiving a signal from a combustion dynamics sensor and providing an output signal and a combustion dynamics control system for controlling combustion dynamics based on the output signal. The control system is associated with a purge-air flow and comprises an acoustic driver, or a flow-manipulating device, or both to perturb the purge-air flow entering the combustor can for controlling combustion dynamics.

Abstract: A method is provided for operating a gas turbine in a power station in which limits of the operating concept, which provide limits for optimization of the power station operation in respect of efficiency, service life consumption, emissions and power provision to the grid system, are adapted during operation. In particular, temperature limits and compressor inlet guide vane position limits are varied as a function of the optimization aims. A gas turbine power station is also provided for carrying out the method.

Abstract: A system and way for controlling a gas turbine engine in the event of a partial or full load rejection from a generator is disclosed. Upon detection of a partial or full load rejection, the fuel flow of the combustor is directed to a secondary circuit of a secondary fuel nozzle to maintain a flame in a downstream chamber of the combustor. By maintaining the flame in the downstream chamber while the engine speed is controlled, the recovery process to a load condition avoids use of spark ignition system and flame detectors in the upstream chamber.

Abstract: A rotary injector (95, 222) comprising one or more radially-extending arms (93) provides for injecting fuel (12, 12.1, 12.4) into a combustion chamber (16). The combustion chamber (16) receives air (14) from locations upstream and down-stream of the rotary injector (95, 222), and the arms (93) of the rotary injector (95, 222) are adapted so that a pressure (P2) in the combustion chamber (16) upstream of the rotary injector (95, 222) is less than a pressure (P0) in a plenum (212) supplying air (14) to the combustion chamber (16) upstream of the rotary injector (95, 222).

Abstract: A method for operating a gas turbine engine system under baseload and/or a high part load conditions is disclosed, the gas turbine engine system includes a gas turbine engine with at least one compressor with at least one row of adjustable variable vanes for control of the inlet air mass flow; at least one combustor; at least one turbine. A control system is provided, which, on the basis of and as a function of at least one measured temperature value measured upstream of the compressor or a measurable quantity directly functionally related thereto, controls the position of the variable vanes such that at least one measured pressure value varying with the angular position of the variable vanes is at a predefined target pressure which is a function of said first temperature.

Abstract: A control apparatus for controlling a compressor driven by a driving unit generating driving power by a gas turbine and an electric motor includes: a temperature detection section for detecting an exhaust gas temperature of the gas turbine; and a control section for generating a motor torque instruction value for the electric motor based on the detected exhaust gas temperature. Such a control apparatus can realize a control so as not to distribute a load on the electric motor when the exhaust gas temperature of the gas turbine is low and a driving power is low. As a result, the operation efficiency can be enhanced.

Abstract: Certain embodiments of the invention may include systems and methods for providing optical interrogation sensors for combustion control. According to an example embodiment of the invention, a method for controlling combustion parameters associated with a gas turbine combustor is provided. The method can include providing an optical path through the gas turbine combustor, propagating light along the optical path, measuring absorption of the light within the gas turbine combustor, and controlling at least one of the combustion parameters based at least in part on the measured absorption.

Abstract: A fuel system includes first and second drive assemblies that are independently drivable relative to one another. The second drive assembly has a speed that is selectively controlled based upon a desired fuel flow. A non-positive displacement pump is driven by the first drive assembly. The non-positive displacement pump provides a desired fuel pressure for the fuel system. A positive displacement pump is driven by the second drive assembly. The positive displacement pump meters a desired volume in response to the speed of the second drive assembly in a first rotational direction. The fuel flows from the pumps and passes through a bypass valve that acts as a minimum pressure shut-off valve. During shut-down of the first drive assembly, the bypass valve is opened by a solenoid and the rotational direction of the second drive assembly is reversed to a second rotational direction to evacuate fuel from the system with the positive displacement pump and return the fuel to the fuel tank.

Abstract: An auto-tune controller and tuning process implemented thereby for measuring and tuning the combustion dynamics and emissions of a GT engine, relative to predetermined upper limits, are provided. Initially, the tuning process includes monitoring the combustion dynamics of a plurality of combustors and emissions for a plurality of conditions. Upon determination that one or more of the conditions exceeds a predetermined upper limit, a fuel flow split to a fuel circuit on all of the combustors on the engine is adjusted by a predetermined amount. The control system continues to monitor the combustion dynamics and to recursively adjust the fuel flow split by the predetermined amount until the combustion dynamics and/or emissions are operating within a prescribed range of the GT engine.

Abstract: A power supply device or system for aeronautics, having a hydrocarbon supply for supplying an engine with hydrocarbon fuel and a hydrogen supply having a fuel reformer for producing hydrogen from hydrocarbon fuel from said hydrocarbon supply. The hydrogen supply is connected to a hydrogen-powered fuel cell for producing electric power and to a hydrogen injecting system for injection of hydrogen into a combustion chamber of the engine. Further, the invention relates to an aircraft having an engine that can be supplied by that power supplying device or system, and to a method for operating said engine.

Abstract: The disclosure relates to a method for operating a gas turbine plant which is supplied with a fuel gas via a compressor station. The compressor station includes a compressor which compresses the fuel gas which is fed via a gas feed line and delivers it via at least one control valve to a combustion chamber of the gas turbine plant. A bypass system is arranged in parallel to the compressor via which fuel gas can be directed in a switchable manner past the compressor to the at least one control valve. An energy-saving operation can be achieved in a simple manner by continuously measuring the fuel gas pressure at the outlet of the at least one control valve. A minimum fuel gas pressure, which is desired (e.g., necessary) for operation of the gas turbine, at the inlet of the at least one control valve is determined from the measured pressure values in each case.

Abstract: A gasification unit provided with a gasification furnace 23 to produce fuel gas production is provided. A combined power generation unit 25 which generates power by rotating a gas turbine and a steam turbine using fuel gas produced in the gasification unit is provided. The combined power generation unit 25 is made operable while fuel change over between fuel gas and an auxiliary fuel as the fuel. A control system is provided in which the degree of opening of a control valve 37 for a flare stack 28 provided in a fuel gas feed line is controlled depending upon the pressure of the fuel gas from the gasification unit when fuel change over from the fuel gas to the auxiliary fuel so as to allow the fuel gas supplied to the combined power generation unit 25 to gradually flare from a flare stack 28 until a flared status that total amount of the fuel gas is reached.

Abstract: According to one aspect, the subject application involves a method of controlling a transition of a gas turbine. The method includes receiving a request of the gas turbine to drive an increased load. The increased load is greater than a load being driven by the gas turbine when the request is received. The method further includes determining that a temperature of a fuel to be ignited within a combustor of the gas turbine is less than a target temperature of the fuel to be introduced into the combustor for driving the increased load. Responsive to this determination, the method also includes controlling introduction of an additive into the combustor of the gas turbine when the temperature of the fuel is less than the target temperature to establish a suitable Wobbe Index of a fuel combination to promote a substantially continuous transition of the gas turbine to drive the increased load, wherein the fuel combination includes the fuel and the additive.

Abstract: A power generation plant comprises a plant control device (600) including two switchable control modes, i.e., a gas-turbine load control mode (7a) and a steam-turbine load control mode (7b). When the control is performed with the gas-turbine load control mode (7a), a fuel valve (104a) is controlled based on a load of a whole generator set (100), and a steam regulating valve (203a) is controlled based on an exhaust pressure of a steam turbine (202a). When the control is performed with the steam-turbine load control mode (7b), the fuel valve (104a) is controlled such that a valve opening degree thereof is maintained constant, and the steam regulating valve (203a) is controlled based on a load of the whole generator set (100).

Abstract: In a gas turbine engine control system having a first valve for regulating the flow rate of fuel in premixed combustion and a second valve for regulating that in diffusion combustion, when the combustion mode is switched from one mode to the other mode, whichever of the first and second valves is associated with the other combustion mew is opened to supply the amount of fuel required for conducting the other combustion mode and, the opening of the valve associated with the one combustion mode is gradually decreased, while that of the other combustion mode is gradually increased, thereby maintaining the total amount of fuel supplied to the engine constant, after elapse of a predetermined period. At the time of switching the combustion mode, therefore, the total amount of fuel supplied to the engine can be accurately controlled to a desired value to minimize engine speed fluctuation.

Abstract: An object is to reduce a fluctuation in the gas-turbine output in a nozzle switching period. In the nozzle switching period during which a first nozzle group that has been used is switched to a second nozzle group that is going to be used, the amounts of fuel supplied through the first nozzle group and the second nozzle group are adjusted by using at least one adjustment parameter registered in advance, the adjustment parameter registered in advance is updated according to the operating condition of the gas turbine, and the updated adjustment parameter is registered as an adjustment parameter to be used next.

Abstract: A method for computer-supported control and/or regulation of a technical system is provided. In the method a reinforcing learning method and an artificial neuronal network are used. In a preferred embodiment, parallel feed-forward networks are connected together such that the global architecture meets an optimal criterion. The network thus approximates the observed benefits as predictor for the expected benefits. In this manner, actual observations are used in an optimal manner to determine a quality function. The quality function obtained intrinsically from the network provides the optimal action selection rule for the given control problem. The method may be applied to any technical system for regulation or control. A preferred field of application is the regulation or control of turbines, in particular a gas turbine.

Abstract: A power extraction system for a gas turbine engine comprises a low spool generator, a high spool generator and a power controller. The low spool generator extracts power from a low spool of the gas turbine engine, and the high spool generator extracts power from a high spool of the gas turbine engine. The power controller receives power extracted by the low spool generator and the high spool generator and distributes the received power to provide an uninterrupted steady state power supply and a transient power supply larger than what is available individually from the low and high spool generators. In another embodiment of the invention, the power extraction system includes an engine controller that operates in conjunction with the power controller to increase inertia energy of the low spool and high spool to increase electric power supply, while engine excursion is reduced and consistent engine thrust is maintained.

Abstract: Aspects of the invention relate to a system and method for operating a turbine engine assembly. The turbine engine assembly has a turbine engine having a compressor section, a combustor section and a turbine section. The combustor section has a lower T_PZ limit and the turbine engine has a design load. The assembly further includes at least one air bleed line from the compressor and at least one valve for controlling air flow through the bleed line. Control structure is provided for opening the valve to allow bleed air to flow through the bleed line when an operating load is less than the design load. The flow rate through the bleed line is increased as the operating load is decreased, reducing the power delivered by the turbine assembly while maintaining the T_PZ above a lower T_PZ limit. A method for operating a turbine engine assembly is also disclosed.

Abstract: A method and system for controlling combustion in a gas turbine engine (10) includes reducing an overall fuel flow provided to a stage (22) of burners (e.g. 34, 35) of the gas turbine engine until reaching a predetermined dynamic operating condition of the first burner of the stage. The method also includes maintaining, while continuing to reduce the overall fuel flow (e.g. 30), a first portion (e.g. 36), of the overall fuel flow delivered to the first burner at a maintenance level so that the predetermined dynamic operating condition of the first burner is maintained.