Adjustable speed gas turbine power generation apparatus and its operation method independent of ambient temperature
AssigneeHitachi, Ltd.
InventorMotoaki Utamura
Life of this patent
Estimating the term…
Abstract
An adjustable speed gas turbine power generation apparatus can maintain a rated output of the gas turbine generation apparatus irrespective of ambient temperature change. For this purpose, the rotational speed of the secondary winding of the generator is controlled by the gas turbine and alternating current excitation of the secondary winding is determined on the basis of the ambient temperature. The sucked air quantity (flow rate by weight) in the compressor can be increased by increasing the rotational speed of the gas turbine when the ambient temperature increases, so that an output from the gas turbine becomes nearly the rated output, while maintaining the desired frequency at the primary winding.
Claims15
An adjustable speed gas turbine power generation apparatus comprising:
- a compressor for intaking and compressing air;
- a combustor for combusting fuel with the intake air from the compressor to generate combustion gas;
- a gas turbine driven by the generated combustion gas;
- a fuel control device for controlling an amount of fuel to be supplied to the combustor in response to a load demand signal;
- a power generator having a primary winding connected to a power transmission system and a secondary winding which is excited with alternating current;
- and wherein
- the generator and compressor are connected to said gas turbine by a drive shaft;
- and
- the power generator is an adjustable speed power generator operating in accordance with the equation fe=fo-f1 wherein fe is a slip frequency of the generator equalling a frequency of excitation current applied by the alternating current excitation device to the secondary winding, fo equals the frequency of electrical current produced by the primary winding and f1 is the frequency of the drive shaft, and an alternating current excitation device is coupled to the secondary winding for controlling the slip frequency fe as a function of the ambient temperature to increase with decreasing ambient temperature.
A method of operating an adjustable speed gas turbine power generation apparatus having a compressor for intaking and compressing air, a combustor for combusting fuel with the intake air to generate combustion gas, a gas turbine driven by the generated combustion gas, a fuel control device for controlling an amount of fuel to be supplied to the combustor in response to a load demand signal, a generator having a primary winding connected to a power transmission system and a secondary winding which is excited with alternating current, wherein the generator is connected to said gas turbine by a drive shaft with the power generator being a variable speed power generator operating in accordance with the equation fe=fo-f1 wherein fe is a slip frequency of the generator equalling a frequency of excitation current applied by an alternating current excitation device to the secondary winding, fo equals the frequency of electrical current produced by the primary winding and f1 is the frequency of the drive shaft, the method comprising the steps:
- controlling the rotational speed of the power generator in response to at least the ambient temperature of the air and a load demand signal and controlling the slip frequency fe with an alternating current excitation device as a function of the ambient temperature to increase with decreasing ambient temperature.
A combined cycle system comprising:
- a gas turbine power generation apparatus;
- a heat recovery steam generator for recovering heat discharged from the gas turbine power generation apparatus;
- a steam turbine driven by a steam heated by the recovered heat from said heat recovery system generator;
- and
- a second power generator driven by the steam turbine;
- said gas turbine power generation apparatus comprising:
- a compressor for intaking and compressing air;
- a combustor for combusting fuel with the intake air from the compressor to generate combustion gas;
- a gas turbine driven by the generated combustion gas;
- a fuel control device for controlling an amount of fuel to be supplied to the combustor in response to a load demand signal;
- a power generator having a primary winding connected to a power transmission system and a secondary winding which is excited with alternating current;
- and wherein
- said power generator is connected by a drive shaft to said gas turbine;
- and
- the power generator is a variable speed power generator operating in accordance with the equation fe=fo-f1 wherein fe is a slip frequency of the generator equalling a frequency of excitation current applied by an alternating current excitation device to the secondary winding, fo equals the frequency of electrical current produced by the primary winding and f1 is the frequency of the drive shaft, the alternating current excitation device controlling the slip frequency fe as a function of the ambient temperature to increase with decreasing ambient temperature.
A method of operating an adjustable speed gas turbine power generation apparatus having a compressor for intaking and compressing air, a combustor for combusting fuel with the intake air to generate combustion gas, a gas turbine driven by the generated combustion gas, a fuel control device for controlling an amount of fuel to be supplied to the combustor in response to a load demand signal, a power generator having a primary winding connected to a power transmission system and a secondary winding which is excited with alternating current, wherein the generator is connected to said gas turbine by a drive shaft, the method comprising the steps:
- controlling the rotational speed of the power generator in response to ambient temperature of the air and a load demand signal with an output of the gas turbine being maintained at substantially a rated output level at different ambient temperatures;
- adjusting the speed of the power generator to operate in accordance with the equation fe=fo-f1 wherein fe is a slip frequency of the power generator equalling a frequency of excitation current applied by an alternating current excitation device to the secondary winding, fo equals the frequency of electrical current produced by the primary winding and f1 is the frequency of the drive shaft;
- and
- controlling the slip frequency fe of the alternating current excitation device as a function of the ambient temperature to increase with decreasing ambient temperature.
A combined cycle system comprising:
- a gas turbine power generation apparatus of the gas turbine power generator apparatus including a compressor for intaking and compressing air, a combustor for combusting fuel with the intake air from the compressor to generate combustion gas, a gas turbine driven by the generated combustion gas, a fuel control device for controlling an amount of fuel to be supplied to the combustor in response to a load demand signal, a power generator having a primary winding connected to a power transmission system and a secondary winding which is excited with alternating current;
- a heat recovery steam generator for recovering heat discharged from the gas turbine power generation apparatus;
- a steam turbine driven by a steam heated by the recovered heat from the heat recovery steam generator;
- a second power generator driven by the steam turbine;
- means for controlling the rotational speed of the power generator to adjust an output of the gas turbine in response to the load demand signal and ambient temperature of the air;
- and,
- a drive shaft connecting said power generator to the gas turbine;
- and wherein
- the power generator is an adjustable speed power generator operating in accordance with the equation fe=fo-f1 wherein fe is a slip frequency of the generator equalling a frequency of excitation current applied by the alternating current excitation device to the secondary winding, fo equals the frequency of electrical current produced by the primary winding and f1 is the frequency of the drive shaft, the alternating current excitation device controlling the slip frequency fe as a function of the ambient temperature to increase with decreasing ambient temperature.
Dependencies are inferred from the claim text.