Method for regulating a turbomachine

Patent metadata

Field	Value
Publication number	US-12467413-B2
Application number	US-202218577641-A
Country	US
Kind code	B2
Filing date	Jul 5, 2022
Priority date	Jul 9, 2021
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A turbomachine may include a high-pressure turbine connected to a high-pressure shaft and a low-pressure turbine connected to a low-pressure shaft, the hot gases leaving the high-pressure turbine driving the low-pressure turbine. A method for regulating the turbomachine includes electrically assisting the high-pressure shaft in order to provide said high-pressure shaft with electrical energy in addition to thermal energy obtained from a combustion chamber of the turbomachine, for an assistance period, and correcting the speed of the low-pressure shaft to achieve a reference speed of the low-pressure shaft that was previously determined in the absence of electrical assistance.

First claim

The invention claimed is:

1 . Method for regulating a turbomachine, the turbomachine comprising an electric machine, a combustion chamber, a high-pressure turbine connected to a high-pressure shaft and a low-pressure turbine connected to a low-pressure shaft, wherein hot gases exiting the high-pressure turbine drive the low-pressure turbine, the method comprising:
assisting the high-pressure shaft by means of the electric machine, in order to provide said high-pressure shaft with mechanical energy coming from electrical energy supplied to the electric machine, to supplement thermal energy coming from the combustion chamber of the turbomachine, during an assistance period; determining, during the assistance period, an energy deficit at an outlet of the high-pressure turbine, as a function of a difference between the power of the hot gases and a reference power of the hot gases in absence of electrical assistance; calculating a collectable mechanical torque at the high-pressure shaft to be collected by means of the electric machine, as a function of said energy deficit; and correcting a speed of the low-pressure shaft by collecting said collectable mechanical torque from the high-pressure shaft, by means of the electric machine, at the end of the assistance period in order to reach a reference speed of the low-pressure shaft that was previously determined in absence of electrical assistance by the electric machine.

2 . The method according to claim 1 , comprising:
determining, during the assistance period, an energy deficit at an outlet of the high-pressure turbine, as a function of a difference between the power of the hot gases and a reference power of the hot gases in absence of electrical assistance; calculating a collectable mechanical torque at the high-pressure shaft to be collected by means of the electric machine, as a function of said energy deficit; and collecting said collectable mechanical torque from the high-pressure shaft, by means of the electric machine, at the end of the assistance period.

3 . The method according to claim 2 , wherein determining the energy deficit comprises:
for each instant of the assistance period, calculating a difference between the power of the hot gases and the reference power of the hot gases in the absence of electrical assistance; and calculating the energy deficit by integrating the calculated differences over the assistance period.

4 . The method according to claim 2 , wherein calculating the collectable mechanical torque comprises:
providing a target instant for reaching the reference speed of the low-pressure shaft; calculating a mean power as a function of the energy deficit and the target instant; and calculating the collectable mechanical torque to be collected by means of the electric machine as a function of the mean power, in order to supply said mean power to the low-pressure shaft.

5 . The method according to claim 2 , wherein the turbomachine comprises an electric motor configured to supply a mechanical assistance torque by means of the electric machine to the high-pressure shaft, wherein the power of the hot gases is determined as a function of the speed of the high-pressure shaft and of the mechanical assistance torque generated by means of the electric machine, and wherein the reference power of the hot gases is previously determined as a function of the speed of the high-pressure shaft when the mechanical assistance torque generated by means of the electric machine is zero.

6 . Turbomachine comprising an electric machine, a combustion chamber, a high-pressure turbine connected to a high-pressure shaft and a low-pressure turbine connected to a low-pressure shaft, the turbomachine further comprising a device configured for correcting the speed of the low-pressure shaft in accordance with the method of claim 1 .

7 . Method for regulating a turbomachine, the turbomachine comprising an electric machine, a combustion chamber, a high-pressure turbine connected to a high-pressure shaft and a low-pressure turbine connected to a low-pressure shaft, wherein hot gases exiting the high-pressure turbine drive the low-pressure turbine, the method comprising:
assisting the high-pressure shaft by means of the electric machine, in order to provide said high-pressure shaft with mechanical assistance torque coming from electrical energy supplied to the electric machine, to supplement thermal energy coming from the combustion chamber of the turbomachine, during an assistance period; determining a correction coefficient as a function of the mechanical assistance torque generated by means of the electric machine; and correcting a speed of the low-pressure shaft by regulating the speed of the high-pressure shaft as a function of the correction coefficient in order to reach a reference speed of the low-pressure shaft that was previously determined in absence of electrical assistance by the electric machine.

8 . The method according to claim 7 , wherein the turbomachine comprises an electric motor configured to provide a mechanical assistance torque by means of the electric machine to the high-pressure shaft during the assistance period, and the method comprises:
determining a correction coefficient as a function of the mechanical assistance torque generated by means of the electric machine; and regulating the speed of the high-pressure shaft as a function of the correction coefficient.

9 . The method according to claim 8 , wherein the correction coefficient is determined as a function of:
the speed of the high-pressure shaft at an operating instant of the turbomachine; and a corrected speed of the high-pressure shaft.

10 . The method according to claim 9 , wherein the correction coefficient is a ratio between the speed of the high-pressure shaft at the operating instant of the turbomachine and the corrected speed of the high-pressure shaft.

11 . The method according to claim 9 , wherein the corrected speed of the high-pressure shaft is determined by, for an operating instant of the turbomachine:
measuring the speed of the high-pressure shaft at said operating instant; determining the reference power of the hot gases which corresponds to the speed of the high-pressure shaft for said operating instant in the absence of electrical assistance; and determining the corrected speed of the high-pressure shaft as a function of the reference power of the hot gases and of the mechanical assistance torque generated by means of the electric machine at said operating instant.

12 . The method according to claim 11 , wherein measuring the speed of the high-pressure shaft at said operating instant is performed during the electrical assistance period.

13 . The method according to claim 8 , wherein regulating the speed of the high-pressure shaft comprises:
providing an acceleration path for the high-pressure shaft; applying the correction coefficient to the acceleration path of the high-pressure shaft; and controlling the speed of the high-pressure shaft to follow the path of the corrected acceleration path of the high-pressure shaft.

Assignees

• Safran

Inventors

• Bidan Guillaume François Daniel
• Ferrand Antoine Pierre Emmanuel

Classifications

• F05D2270/044

  by making it as high as possible · CPC title

• F05D2270/023

  of different spools or shafts · CPC title

• F01D21/14

  responsive to other specific conditions · CPC title

• F01D15/10

  Adaptations for driving, or combinations with, electric generators · CPC title

• F05D2270/101

  Compressor surge or stall · CPC title