Low pressure compressor control for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-12331689-B2
Application number	US-202218072336-A
Country	US
Kind code	B2
Filing date	Nov 30, 2022
Priority date	Dec 10, 2018
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

A gas turbine engine includes a low speed spool mechanically interconnecting a low pressure turbine and at least one of a fan and a prop, a high speed spool mechanically interconnecting a high pressure turbine and a high pressure compressor, and an epicyclic gear system mechanically coupled to the high speed spool. The gas turbine engine also includes a low pressure compressor mechanically coupled to the high speed spool via the epicyclic gear system. The low pressure compressor may be mechanically independent of the low speed spool. The gas turbine engine may include a plurality of motor-generators for transferring power between the high speed spool and the low pressure compressor.

First claim

What is claimed is:

1. A method of operating a gas turbine engine, the method comprising:
determining, by one or more processors, a first operating speed of a high speed spool of the gas turbine engine; and
based on the first operating speed, controlling, by the one or more processors, a second operating speed of a low pressure compressor of the gas turbine engine, wherein the low pressure compressor is mechanically independent of a low speed spool of the gas turbine engine, wherein:
determining the first operating speed of the high speed spool comprises determining a first rate of change of the first operating speed, and
in response to the first rate of change increasing, the second operating speed of the low pressure compressor of the gas turbine engine is increased via a motor generator.

2. The method of claim 1 , wherein a fraction of mechanical rotational energy of the high speed spool is transferred via the motor generator to the low pressure compressor.

3. A method of operating a gas turbine engine, the method comprising:
determining, by one or more processors, a first operating speed of a high speed spool of the gas turbine engine; and
based on the first operating speed, controlling, by the one or more processors, a second operating speed of a low pressure compressor of the gas turbine engine, wherein the low pressure compressor is mechanically independent of a low speed spool of the gas turbine engine, wherein:
determining the first operating speed of the high speed spool comprises determining a first rate of change of the first operating speed, and
in response to the first rate of change decreasing, a second rate of change of the second operating speed of the low pressure compressor of the gas turbine engine is reduced faster than the first rate of change of the first operating speed.

4. The method of claim 3 , wherein a fraction of a mechanical rotational energy of the low pressure compressor, a gear carrier, and a sun gear are respectively transferred via a first motor generator and a second motor generator to a third motor generator to increase a rate of deceleration of the low pressure compressor.

5. The method of claim 4 , wherein in response to the fraction of the mechanical rotational energy being transferred, a power of a low pressure turbine is reduced to generate a reduced thrust output of the gas turbine engine.

6. A control system including a tangible, non-transitory computer-readable storage medium having instructions stored thereon that, in response to execution by one or more processors, causes the one or more processors to perform operations comprising:
determining, by the one or more processors, a first operating speed of a high speed spool of a gas turbine engine; and
based on the first operating speed, controlling, by the one or more processors, a second operating speed of a low pressure compressor of the gas turbine engine, wherein the low pressure compressor is mechanically independent of a low speed spool of the gas turbine engine, wherein:
the controlling the second operating speed further comprises determining, by the one or more processors, a first rate of change of the first operating speed, and
in response to the one or more processors determining the first rate of change is increasing, commanding, by the one or more processors, a first motor generator and a second motor generator to transfer a first fraction of a first mechanical rotational energy of the low pressure compressor to a third motor generator to improve a stability of a high pressure compressor.

7. The control system of claim 6 , wherein in response to the one or more processors determining the first rate of change is decreasing, commanding, by the one or more processors, the first motor generator and the second motor generator to transfer a second fraction of a second mechanical rotational energy of the low pressure compressor to the third motor generator to increase a first rate of deceleration of the low pressure compressor and reduce a second rate of deceleration of the high speed spool.

8. The control system of claim 7 , wherein:
the first motor generator is mechanically coupled to a sun gear of an epicyclic gear system,
the second motor generator is mechanically coupled to a gear carrier of the epicyclic gear system, and
the third motor generator is mechanically coupled to the high speed spool.

9. The control system of claim 6 , wherein in response to the commanding the first motor generator and the second motor generator to transfer the first fraction of the first mechanical rotational energy of the low pressure compressor to the third motor generator, the first fraction of the first mechanical rotational energy is transferred to the third motor generator through an epicyclic gear system.

10. The gas turbine engine comprising the control system of claim 6 , wherein:
the control system is configured for electrical communication with the first motor generator, the second motor generator, and the third motor generator, and
the low pressure compressor is mechanically independent of the low speed spool of the gas turbine engine.

11. The gas turbine engine of claim 10 , further comprising the first motor generator, the second motor generator, and the third motor generator, wherein:
the first motor generator is configured to be mechanically coupled to a sun gear of an epicyclic gear system,
the second motor generator is configured to be mechanically coupled to a gear carrier of the epicyclic gear system, and
the third motor generator is configured to be mechanically coupled to the high speed spool.

12. The gas turbine engine of claim 10 , wherein in response to the one or more processors determining the first rate of change is decreasing, commanding, by the one or more processors, the first motor generator and the second motor generator to transfer a second fraction of a second mechanical rotational energy of the low pressure compressor to the third motor generator to increase a first rate of deceleration of the low pressure compressor and reduce a second rate of deceleration of the high speed spool.

13. The gas turbine engine of claim 10 , wherein in response to the commanding the first motor generator and the second motor generator to transfer the first fraction of the first mechanical rotational energy to the third motor generator, the first fraction of the first mechanical rotational energy is transferred to the third motor generator through an epicyclic gear system.

14. The gas turbine engine of claim 10 , wherein the control system is configured to control an epicyclic gear system through the first motor generator, the second motor generator, and the third motor generator.

Assignees

• Raytheon Tech Corp
• Rtx Corp

Inventors

• Kupratis Daniel Bernard

Classifications

• B64D27/24

  using steam or spring force (jet aircraft B64D27/16) · CPC title

• B64D31/18

  for hybrid-electric power plants · CPC title

• B64D27/33

  Hybrid electric aircraft · CPC title

• H02K7/1823

  structurally associated with turbines or similar engines · CPC title

• H02K7/116

  with gears · CPC title