A method of distributing power within a gas turbine engine is disclosed. In various embodiments, the method includes driving a high pressure turbine having a first stage and a second stage with an exhaust stream from a combustor, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; driving a high pressure compressor connected to a high pressure compressor spool via a differential system, the differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear assembly connected to the high pressure compressor spool; and selectively applying an auxiliary input power into at least one of the high pressure compressor spool and the high pressure turbine.

A method of distributing power within a gas turbine engine is disclosed. In various embodiments, the method includes driving a high pressure turbine having a first stage and a second stage with an exhaust stream from a combustor, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; driving a high pressure compressor connected to a high pressure compressor spool via a differential system, the differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear assembly connected to the high pressure compressor spool; and selectively applying an auxiliary input power into at least one of the high pressure compressor spool and the high pressure turbine.

Embodiments of systems and methods for supplying fuel, enabling communications, and conveying electric power associated with operation of a hydraulic fracturing unit of a plurality of hydraulic fracturing units are disclosed and may include a fuel line connection assembly configured to be connected to the first hydraulic fracturing unit and to supply fuel from a fuel source to a gas turbine engine connected to the hydraulic fracturing unit. A system also may include a communications cable assembly configured to be connected to the hydraulic fracturing unit and to enable data communications between the hydraulic fracturing unit and a data center or another hydraulic fracturing unit. A system further may include a power cable assembly configured to be connected to the hydraulic fracturing unit and to convey electric power between the hydraulic fracturing unit and a remote electrical power source or the plurality of hydraulic fracturing units.

Embodiments of systems and methods for supplying fuel, enabling communications, and conveying electric power associated with operation of a hydraulic fracturing unit of a plurality of hydraulic fracturing units are disclosed and may include a fuel line connection assembly configured to be connected to the first hydraulic fracturing unit and to supply fuel from a fuel source to a gas turbine engine connected to the hydraulic fracturing unit. A system also may include a communications cable assembly configured to be connected to the hydraulic fracturing unit and to enable data communications between the hydraulic fracturing unit and a data center or another hydraulic fracturing unit. A system further may include a power cable assembly configured to be connected to the hydraulic fracturing unit and to convey electric power between the hydraulic fracturing unit and a remote electrical power source or the plurality of hydraulic fracturing units.

A gas turbine engine for an aircraft comprises a high-pressure (HP) spool comprising an HP compressor and a first electric machine driven by an HP turbine; a low-pressure (LP) spool comprising an LP compressor and a second electric machine driven by an LP turbine; a combustor; an electrical energy storage unit; and an engine controller configured to: in response to receipt of a request for an increased electrical power supply by the engine (dP.sub.D) within a requested timeframe (dt), evaluating a current HP compressor surge margin (dR.sub.H/R.sub.H) and a current LP compressor surge margin (dR.sub.L/R.sub.L) based on the operating points thereof; in response to evaluating that one or more of the HP compressor and the LP compressor has insufficient surge margin to facilitate a change of electrical power supply at a requested rate (dP.sub.D/dt), meeting the requested electrical power demand using the electrical energy storage unit whilst increasing fuel flow to the combustor to accelerate the engine.

Embodiments of systems and methods for supplying fuel, enabling communications, and conveying electric power associated with operation of a hydraulic fracturing unit of a plurality of hydraulic fracturing units are disclosed and may include a fuel line connection assembly configured to be connected to the first hydraulic fracturing unit and to supply fuel from a fuel source to a gas turbine engine connected to the hydraulic fracturing unit. A system also may include a communications cable assembly configured to be connected to the hydraulic fracturing unit and to enable data communications between the hydraulic fracturing unit and a data center or another hydraulic fracturing unit. A system further may include a power cable assembly configured to be connected to the hydraulic fracturing unit and to convey electric power between the hydraulic fracturing unit and a remote electrical power source or the plurality of hydraulic fracturing units.

Embodiments of systems and methods for supplying fuel, enabling communications, and conveying electric power associated with operation of a hydraulic fracturing unit of a plurality of hydraulic fracturing units are disclosed and may include a fuel line connection assembly configured to be connected to the first hydraulic fracturing unit and to supply fuel from a fuel source to a gas turbine engine connected to the hydraulic fracturing unit. A system also may include a communications cable assembly configured to be connected to the hydraulic fracturing unit and to enable data communications between the hydraulic fracturing unit and a data center or another hydraulic fracturing unit. A system further may include a power cable assembly configured to be connected to the hydraulic fracturing unit and to convey electric power between the hydraulic fracturing unit and a remote electrical power source or the plurality of hydraulic fracturing units.

An engine system comprises first and second electrical generators coupled to lower and higher pressure (LP, HP) shafts respectively of a gas turbine engine. A controller is arranged to receive a signal corresponding to a total electrical power demand P.sub.1 and to output control signals to the electrical generators in response thereto such that the first and second electrical generators output electrical powers (1−y)P.sub.1 and yP.sub.1 respectively when P.sub.1≤P.sub.m1, where 0.5<y≤1 and P.sub.m1 is the maximum electrical output power of the first electrical generator. By satisfying the demand P.sub.1 mostly by extraction of electrical power from the first electrical generator when possible, the additional mechanical stress on the gas turbine engine resulting from electrical power extraction is reduced compared to the case where 50% or more of the demand P.sub.1 is satisfied by the second electrical generator.

An engine system comprises first and second electrical generators coupled to lower and higher pressure (LP, HP) shafts respectively of a gas turbine engine. A controller is arranged to receive a signal corresponding to a total electrical power demand P.sub.1 and to output control signals to the electrical generators in response thereto such that the first and second electrical generators output electrical powers (1−y)P.sub.1 and yP.sub.1 respectively when P.sub.1≤P.sub.m1, where 0.5<y≤1 and P.sub.m1 is the maximum electrical output power of the first electrical generator. By satisfying the demand P.sub.1 mostly by extraction of electrical power from the first electrical generator when possible, the additional mechanical stress on the gas turbine engine resulting from electrical power extraction is reduced compared to the case where 50% or more of the demand P.sub.1 is satisfied by the second electrical generator.

A method for operating a gas turbine engine having a starter-electric generator driven by one of a plurality of shafts of the gas turbine engine is provided. The method includes determining a desired amount of thrust to be produced by the gas turbine engine, as well as a desired amount of electrical power to be generated by the starter-electric generator of the gas turbine engine. The method operates the gas turbine engine to produce the desired amount of thrust, while producing less than the desired amount of electrical power using the starter-electric generator. Producing less than the desired amount of electrical power using the starter-electric generator allows for the desired amount of thrust production, or allows for the desired amount of thrust production more quickly.