Electric propulsion system

• US 10,093,428 B2
• Filed: 08/22/2016
• Issued: 10/09/2018
• Est. Priority Date: 08/22/2016
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Kupiszewski, Thomas, Miller, Brandon Wayne, Vondrell, Randy M.
• Primary Examiner(s): GUGGER, SEAN A
• Application Number:
  US15/242,844
• Publication Number:
  US 20180050807A1
• Time in Patent Office: 778 Days
• CPC Class Codes: B60L 2200/10 Air crafts
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 50/12 using AC generators and DC motors
• CPC Class Codes: B64D 2205/00 Aircraft with means for ground manoeuvring, such as taxiing, using an auxiliary thrust system, e.g. jet-engines, propellers or compressed air
• CPC Class Codes: B64D 2221/00 Electric power distribution systems onboard aircraft
• CPC Class Codes: B64D 27/02 Aircraft characterised by the type or position of power plants fuselages specially adapted for mounting power plants B64C1/16; wings specially adapted for power plants B64C3/32
• CPC Class Codes: B64D 27/026 comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine Hybrid electric aircraft B64D27/33
• CPC Class Codes: B64D 27/24 using steam or spring force jet aircraft B64D27/16
• CPC Class Codes: H02J 1/082 Plural DC voltage, e.g. DC supply voltage with at least two different DC voltage levels
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y02T 50/80 Energy efficient operational measures, e.g. ground operations or mission management
• CPC Class Codes: Y10S 903/902 Prime movers comprising electrical and internal combustion motors

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.

Claims

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 magnitude of the positive DC voltage the baseline voltage magnitude.

16. The propulsion system of claim 15, wherein the electric propulsor is a boundary layer ingestion fan.