Oil pumping control for electrical oil pumping system

Patent metadata

Field	Value
Publication number	US-11629640-B2
Application number	US-202117469845-A
Country	US
Kind code	B2
Filing date	Sep 8, 2021
Priority date	Sep 8, 2021
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

An oil pumping system for use with a gas turbine engine includes an electric machine, an oil pump assembly, and a variable frequency drive controller. The variable frequency drive is connected with the electric machine and the oil pump assembly. The variable frequency drive controller is programmed to control a torque and speed of the pump motor independent of the gas turbine engine speed so that a flow of oil moved by the oil pump assembly is controlled to cool or lubricate components of the gas turbine engine independent of the gas turbine engine speed.

First claim

What is claimed is:

1. A gas turbine engine oil pumping system comprising:
a gas turbine engine that includes a compressor, combustor, and a turbine, the compressor and the turbine configured to rotate about an axis at an engine speed;
an electric machine;
a rectifier connected to the electric machine;
an oil pump assembly configured to provide a flow of oil to the gas turbine engine, the oil pump assembly including an oil pump and a pump motor mechanically coupled to the oil pump and configured to drive the oil pump; and
a variable frequency drive controller electrically connected between the rectifier and the pump motor, the variable frequency drive controller programmed to control a torque and speed of the pump motor independent of the engine speed so that the flow of the oil moved by the oil pump is controlled to cool or lubricate components of the gas turbine engine independent of the engine speed,
wherein the pump motor and variable frequency drive controller are powered from a dedicated independent generator winding from one of a plurality of generator windings on the same rotor, wherein the plurality of generator windings are included in the electric machine.

2. The gas turbine engine oil pumping system of claim 1 , wherein the electric machine providing electrical power is embedded inside the gas turbine engine and driven by an engine shaft with one or more independent electrical windings of the plurality of generator windings.

3. The gas turbine engine oil pumping system of claim 1 , wherein the electric machine is an electric starter generator configured for use in a motor mode to supply electrical energy to the gas turbine engine to start the gas turbine engine and in a generate mode in which the electric machine is configured to generate electrical power in response to being driven by the gas turbine engine.

4. The gas turbine engine oil pumping system of claim 1 , wherein during a start-up phase of the gas turbine engine, the variable frequency drive controller is programmed to limit the torque of the pump motor to a first predetermine torque and to limit the speed of the pump motor to a first predetermined speed to minimize electric current and power of the pump motor and avoid over-pressure of the oil during the start-up phase.

5. The gas turbine engine oil pumping system of claim 1 , wherein during system testing or the start-up phase of the gas turbine engine the variable frequency drive controller is programmed to evaluate the oil pump torque vs. speed curve and hence pressure vs. flow curve relative to the predicted pressure vs flow curve for the measured oil temperature state to determine the health of the oil system.

6. The gas turbine engine oil pumping system of claim 1 , wherein the variable frequency drive controller determines a temperature of a component of the gas turbine engine and increases the flow of oil by increasing the oil pump speed in response to the temperature of the component being greater than a predetermined value.

7. The gas turbine engine oil pumping system of claim 6 , wherein the oil pump assembly includes a heat exchanger and the flow of oil is configured to pass through the heat exchanger to cool the flow of oil.

8. The gas turbine engine oil pumping system of claim 7 , wherein the variable frequency drive controller is programmed to increase the flow of oil to increases an oil pressure of the flow of oil to open a pressure activated oil valve to provide additional oil flow to the heat exchanger with the increased oil pressure.

9. The gas turbine engine oil pumping system of claim 8 , wherein the variable frequency drive controller is programmed to provide closed loop temperature control by varying a speed of the oil pump.

10. The gas turbine engine oil pumping system of claim 1 , wherein one of an oil cooled engine component temperature and an engine oil temperature is controlled via closed loop by varying the oil pump speed.

11. The gas turbine engine oil pumping system of claim 1 , wherein the variable frequency drive controller is programmed to increase the flow of oil to open a pressure activated oil valve to provide additional cooling flow to a component of the gas turbine engine at a higher oil pressure such that further increases in a speed of the oil pump results in more flow through the pressure activated oil valve to cool the component.

12. The gas turbine engine oil pumping system of claim 11 , wherein the variable frequency drive controller is programmed to provide closed loop temperature control by using the oil pump speed to control the flow of oil using the pressure activated oil valve.

13. A gas turbine engine oil pumping system comprising:
a gas turbine engine that includes a compressor, combustor, and a turbine, the compressor and the turbine configured to rotate about an axis at an engine speed;
an electric machine;
a rectifier connected to the electric machine;
an oil pump assembly configured to provide a flow of oil to the gas turbine engine, the oil pump assembly including an oil pump and a pump motor mechanically coupled to the oil pump and configured to drive the oil pump; and
a variable frequency drive controller electrically connected between the rectifier and the pump motor, the variable frequency drive controller programmed to control a torque and speed of the pump motor independent of the engine speed so that the flow of the oil moved by the oil pump is controlled to cool or lubricate components of the gas turbine engine independent of the engine speed,
wherein the variable frequency drive controller is programmed to determine an active torque versus speed curve of the pump motor during use of the pump motor, compare the active torque versus speed curve to a predetermined baseline torque versus speed curve, and generate a signal in response to a difference between the active torque versus speed curve and the baseline torque versus speed curve being greater than a preset value.

14. A method for use with a gas turbine engine, the method comprising:
rotating a compressor and a turbine of the gas turbine engine about an axis at an engine speed;
generating electric power using an electric machine;
supplying electric power to a pump motor connected to an oil pump;
pumping oil from the oil pump to the gas turbine engine; and
varying the electric power supplied to the pump motor to control a torque and speed of the pump motor independent of the engine speed,
further comprising determining a temperature of a flow of the oil and increasing a speed of the pump motor in response to the temperature of the oil being greater than a predetermined temperature value.

15. The method of claim 14 , further comprising, during a start-up phase of the gas turbine engine, limiting the torque of the pump motor to a first predetermine torque and limiting the speed of the pump motor to a first predetermined speed to minimize electric power and current of the pump motor and control the maximum pressure of the oil during the start-up phase.

16. The method of claim 14 , further comprising determining an active torque versus speed curve of the pump motor during use of the pump motor, comparing the active torque versus speed curve to a predetermined baseline torque versus speed curve, and generating a signal in response to a difference between the active torque versus speed curve and the baseline torque versus speed curve being greater than a preset value.

17. The method of claim 14 , further comprising determining a temperature of a component included in the gas turbine engine and increasing a speed of the pump motor in re

Assignees

• Rolls Royce Nam Tech Inc

Inventors

• Smith Alan W

Classifications

• F05D2220/76

  an electrical generator · CPC title

• F02C3/04

  having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) · CPC title

• F05D2270/303

  Temperature · CPC title

• F02C7/16 Primary

  characterised by cooling medium · CPC title

• F05D2260/98

  Lubrication · CPC title