Method for providing emergency reserve power using storage techniques for electrical systems applications

A method of operating combustion turbine power generation system including (1) a modified simple cycle combustion turbine system optimized for a "hot" stand-by reserve mode of operation and having a power shaft assembly including a compressor, an expansion turbine, and a double-ended motor/generator between said compressor and said turbine, said motor/generator having a turbine driving clutch structure on one end thereof and a compressor driving clutch structure on the other end thereof, said compressor driving clutch structure being operatively associated with said compressor so that said compressor is driven by said motor/generator when said compressor driving clutch structure is engaged and said turbine driving clutch structure being operatively associated with said turbine so that said motor/generator may be driven by said turbine when said turbine driving clutch structure is engaged, and a combustor feeding said expansion turbine, and (2) an additional system having a boost compressor and an intercooler feeding cooled air to said boost compressor with an outlet of the compressor of the power shaft assembly being connected to an inlet of said intercooler via flow path structure, an electric motor for driving said boost compressor, an aftercooler downstream of said boost compressor, a compressed air storage downstream of said aftercooler, connection structure permitting communication between an outlet of said air storage and an inlet to the combustor, bypass structure having a first end coupled to said flow path structure and a second end coupled to said connection structure, said bypass structure permitting communication between an output of said compressor and an inlet of said combustor, a first valve system for controlling air flow in said flow path structure and disposed between said compressor and said intercooler feeding the boost compressor, a second valve system for controlling air flow in said connection structure and disposed between said air storage and said combustor, and a third valve system for controlling air flow in said bypass structure, said system integrating said modified simple cycle combustion turbine system and said additional system, the method including:

• controlling said valve systems to permit alternative flow path arrangements and controlling said clutch structures to provide one of
• (a) a "hot" stand-by reserve mode of operation wherein said turbine driving clutch structure of said power shaft assembly is engaged and said compressor driving clutch structure is disengaged such that said turbine drives said motor/generator with the turbine operating with the motor/generator synchronized with substantially zero power generated to an electric grid, said first and third valve systems are closed and said second valve system is partially open to provide minimal air flow to said combustor to have said turbine driven motor/generator synchronized with an electric grid so as to deliver emergency electric power at full turbine power within seconds upon further opening of said second valve system,
• (b) a "cold" stand-by reserve mode of operation wherein said compressor driving clutch structure is disengaged and said turbine driving clutch structure is engaged such that said turbine is ready to drive the motor/generator, said first, second and third valve systems are closed with said second valve system ready to be opened to define an air and gas flow path where compressed air stored in said air storage may move to the combustor and gas may move to said turbine for cold start-up thereof to provide electric power at full turbine power of specified duration within minutes, as a function of heating requirements of said turbine,
• (c) an emergency power generation mode of operation wherein said compressor driving clutch structure is disengaged and said turbine driving clutch structure is engaged such that said turbine drives the motor generator, said first and third valve systems are closed and said second valve system is open so as to define an air and gas flow path where compressed air from said air storage moves to said combustor and then gas moves to the turbine of the power shaft assembly to produce emergency power at full turbine power of specified duration,
• (d) a combustion turbine emergency power generation mode of operation wherein said first and second valve systems are closed and said third valve system is open, said compressor driving clutch structure and said turbine driving clutch structure each being engaged, and compressed air from said compressor moves through said bypass structure and to said combustor and then gas moves to said turbine to produce power of unlimited duration at a fraction of said full power of said turbine, and
• (e) a charging mode of operation wherein said turbine driving clutch structure is disengaged and said compressor driving clutch structure of said at least one power shaft assembly is engaged such that said compressor is driven by said motor/generator, said second and third valve systems are closed and said first valve system is open so as to define an air flow path where compressed air from said compressor moves along said flow path structure and through said intercooler and is then further compressed in said boost compressor and cooled in the aftercooler, the compressed air thereafter is charged into the air storage, said motor/generator and said electric motor being coupled to and powered by an electric grid.

A combustion turbine power generation system to provide emergency power at an electric substation comprising:

• a modified simple cycle combustion turbine power generation system optimized for a "hot" stand-by reserve mode of operation and having a power shaft assembly including a compressor, an expansion turbine, and a double-ended motor/generator between said compressor and said turbine, said motor/generator having a turbine driving clutch structure on one end thereof and a compressor driving clutch structure on the other end thereof, said compressor driving clutch structure being operatively associated with said compressor so that said compressor is driven by said motor/generator when said compressor driving clutch structure is engaged and said turbine driving clutch structure being operatively associated with said turbine so that said motor/generator may be driven by said turbine when said turbine driven clutch structure is engaged, and a combustor feeding said expansion turbine, and
• an additional system having a boost compressor, an intercooler feeding cooled air to said boost compressor an electric motor for driving said boost compressor, and aftercooler downstream of said boost compressor, a compressed air energy storage downstream of said aftercooler,
• said additional system being integrated with said modified simple cycle combustion turbine power generation system by flow path structure permitting communication between an outlet of said compressor and an inlet to said intercooler feeding said boost compressor and connection structure permitting communication between an outlet of said air storage and an inlet to the combustor,
• said system further including:
• bypass structure having a first end coupled to said flow path structure and a second end coupled to said connection structure, said bypass structure permitting communication between an output of said compressor and an inlet of said combustor
• a first valve system for controlling air flow in said flow path structure and disposed between said compressor and an inlet to said intercooler feeding said boost compressor,
• a second valve system for controlling air flow in said connection structure and disposed between said air storage and said combustor, and
• a third valve system for controlling air flow in said bypass structure,
• said valve systems being controllable to provide various flow paths through said system and said turbine driving clutch structure and said compressor driving clutch being controllable so as to selectively provide (i) a "hot" stand-by reserve mode of operation capable of delivering emergency electrical power of specified duration, at full power of said turbine, within seconds (ii) a "cold" stand-by reserve mode of operation to provide emergency power of specified duration, at full power of said turbine, within minutes (iii) an emergency power generation mode of operation capable of providing emergency power of specified duration at full power of said turbine, (iv) a combustion turbine emergency power supply mode to provide emergency power of unlimited duration at a fraction of said full power of said turbine, and (v) a charging mode of operation wherein said air storage is charged with compressed air.