Electric propulsion system

Patent metadata

Field	Value
Publication number	US-10093428-B2
Application number	US-201615242844-A
Country	US
Kind code	B2
Filing date	Aug 22, 2016
Priority date	Aug 22, 2016
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A propulsion system includes an electric propulsor and a gas turbine engine. The propulsion system also includes an electric machine coupled to a rotary component of the gas turbine engine generating a voltage at a baseline voltage magnitude during operation of the gas turbine engine. An electric communication bus is provided electrically connecting the electric machine to the electric propulsor. The propulsion system additionally includes a means for providing a differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude.

First claim

What is claimed is:

1. A propulsion system for an aeronautical device comprising:
an electric propulsor;
a gas turbine engine comprising a compressor section, a turbine section, and a rotary component rotatable with at least a portion of the compressor section and with at least a portion of the turbine;
a first electric machine coupled to the rotary component of the gas turbine engine, the first electric machine generating a positive voltage at a baseline voltage magnitude during operation of the gas turbine engine;
an electric communication bus electrically connecting the first electric machine to the electric propulsor; and
a means for providing a differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude, the means for providing a differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude comprising a second electric machine electrically connected to the electric communication bus and generating a negative voltage at the baseline voltage magnitude during operation and the electric communication bus further electrically connecting the second electric machine to the electric propulsor, the negative voltage at the baseline voltage magnitude and the positive voltage at the baseline voltage magnitude generating the differential voltage equal to about twice the baseline voltage magnitude.

2. The propulsion system of claim 1 , wherein the means for providing the differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude comprises the first electric machine being configured as a center-tapped to ground electric machine.

3. The propulsion system of claim 1 , wherein the gas turbine engine is a first gas turbine engine, wherein the means for increasing the baseline voltage level further comprises:
a second gas turbine engine comprising a rotary component, wherein the
second electric machine is coupled to the rotary component of the second gas turbine engine and electrically connected to the electric communication bus.

4. The propulsion system of claim 3 , wherein the first and second electric machines are each AC electric generators, wherein the means for providing the differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude further comprises the electric communication bus including at least one AC-to-DC converter for converting the voltages generated by the first and second electric machines to a positive DC voltage substantially equal in magnitude to the baseline voltage magnitude and a negative DC voltage substantially equal in magnitude to the baseline voltage magnitude.

5. The propulsion system of claim 4 , wherein the means for providing the differential voltage to the electric propulsor equal to about twice the baseline voltage magnitude further comprises the electric communication bus including a DC-to-AC converter for converting the positive DC voltage and the negative DC voltage to an AC voltage defining a net differential voltage equal to about twice the baseline voltage magnitude.

6. The propulsion system of claim 3 , wherein the first gas turbine engine is an under-wing mounted gas turbine engine, wherein the second gas turbine engine is also an under-wing mounted gas turbine engine, and wherein the electric propulsor is an aft fan.

7. The propulsion system of claim 3 , wherein the first and second electric machines are each DC electric generators, wherein the first electric machine is configured to generate a positive DC voltage, wherein the second electric machine is configured to generate a negative DC voltage, wherein the positive DC voltage is substantially the same magnitude as the negative DC voltage.

8. The propulsion system of claim 1 , wherein the compressor section and the turbine section of the gas turbine engine together define at least in part a core air flowpath, wherein the electric machine is positioned at least partially inward of the core air flowpath along a radial direction of the gas turbine engine, and wherein the electric machine is mounted at least partially within or aft of the turbine section along an axial direction of the gas turbine engine.

9. The propulsion system of claim 1 , wherein the electric machine is an electric generator, and wherein the baseline voltage magnitude is at least about 500 volts of electrical power.

10. The propulsion system of claim 1 , wherein the electric communication bus comprises an intermediate section, wherein the intermediate section comprises an electric cable positioned within a conduit containing a cooling fluid.

11. The propulsion system of claim 1 , further comprising:
a cooling system, wherein the electric communication bus includes a first juncture block for electrically connecting an intermediate section of the electric communication bus to the electric machine, wherein the cooling system is configured to actively cool the first juncture block, and wherein the intermediate section is an uncooled section of the electric communication bus.

12. A propulsion system for an aeronautical device comprising:
an electric propulsor;
a first gas turbine engine comprising a rotary component;
a first electric machine coupled to the rotary component of the first gas turbine engine, the first electric machine being a center-tapped to ground AC electric generator;
a second gas turbine engine comprising a rotary component; and
a second electric machine coupled to the rotary component of the second gas turbine engine, the second electric machine being a center-tapped to ground AC electric generator; and
an electric communication bus electrically connecting the first electric machine and second electric machine to the electric propulsor, the electric communication bus comprising at least one AC-to-DC converter for converting an AC voltage from the first electric machine to a positive DC voltage and an AC voltage from the second electric machine to a negative DC voltage for powering the electric propulsor.

13. The propulsion system of claim 12 , wherein the AC voltages from the first and second electric machine each define a baseline voltage magnitude, and wherein the positive DC voltage and the negative DC voltage define a net differential voltage equal to about twice the baseline voltage magnitude.

14. The propulsion system of claim 12 , wherein the AC voltages from the first and second electric machine each define a baseline voltage magnitude, and wherein the electric communication bus further comprises a DC-to-AC converter for converting the positive DC voltage and the negative DC voltage to an AC voltage defining a net differential voltage equal to about twice the baseline voltage magnitude.

15. A propulsion system for an aeronautical device comprising:
an electric propulsor;
a first gas turbine engine comprising a rotary component;
a first electric machine coupled to the rotary component of the first gas turbine engine, the first electric machine being a DC electric generator configured to generate a positive DC voltage substantially at a baseline voltage magnitude;
a second gas turbine engine comprising a rotary component; and
a second electric machine coupled to the rotary component of the second gas turbine engine, the second electric machine being a DC electric generator configured to generate a negative DC voltage substantially at the baseline voltage magnitude; and
an electric communication bus electrically connecting the first electric machine and second electric machine to the electric propulsor to provide the electric propulsor a net differential voltage equal to about twice a m

Assignees

• Gen Electric

Inventors

• Kupiszewski Thomas
• Miller Brandon Wayne
• Vondrell Randy M

Classifications

• B64D33/08

  of power plant cooling systems · CPC title

• B64D27/24 Primary

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

• B64D27/10

  of gas-turbine type  (jet aircraft B64D27/16) · CPC title

• B64D27/02 Primary

  Aircraft characterised by the type or position of power plants · CPC title

• B64D2221/00

  Electric power distribution systems onboard aircraft · CPC title