SELECTIVELY REGULATING CURRENT IN DISTRIBUTED PROPULSION SYSTEMS

• US 20190009920A1
• Filed: 10/16/2017
• Published: 01/10/2019
• Est. Priority Date: 07/10/2017
• Status: Active Grant

• Current Assignee: Rolls-Royce North American Technologies, Inc. (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce North American Technologies, Inc. (Rolls-Royce Holdings Plc)
• Inventors: Armstrong, Michael James, Bollman, Andrew Mark, Loder, David
• Granted Patent: US 10,640,225 B2
• Time in Patent Office: Days
• 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: B64D 31/06 actuated automatically
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: H02J 3/007 Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing uninterruptable power supply H02J9/00
• CPC Class Codes: H02J 3/06 Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
• CPC Class Codes: H02J 3/12 for adjusting voltage in ac networks by changing a characteristic of the network load
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A distributed propulsion system includes a first propulsor and a second propulsor, a first generator configured to generate a first AC current, and a second generator configured to generate a second AC current. The system includes a power regulation circuit. The power regulation circuit includes a first current path that includes a first power electronics circuit, a second current path that includes a second power electronics circuit, a third current path that bypasses the first and second power electronics circuits, and a fourth current path that bypasses the first and second power electronics circuits. The power regulation circuit also includes a plurality of switches configured to selectively couple each respective input to a respective selected output to cause a respective current to flow from the respective input to the respective selected output via one of the first current path, second current path, third current path, or fourth current path.

Claims

1. A distributed propulsion system, comprising:

a first propulsor and a second propulsor;

a first generator configured to generate a first AC current;

a second generator configured to generate a second AC current; and

a power regulation circuit electrically coupled to the first propulsor via a first output, the second propulsor via a second output, the first generator via a first input, and the second generator via a second input, wherein the power regulation circuit comprises;

a first current path comprising a first power electronics circuit,

a second current path comprising a second power electronics circuit,

a third current path that bypasses the first and second power electronics circuits,

a fourth current path that bypasses the first and second power electronics circuits, and

a plurality of switches configured to selectively couple each respective input to a respective selected output to cause a respective current to flow from the respective input to the respective selected output via one of the first current path, the second current path, the third current path, or the fourth current path.

2. The distributed propulsion system of claim 1,

wherein the first power electronics circuit comprises a first rectifier electrically coupled to a first inverter, and

wherein the second power electronics circuit comprises a second rectifier electrically coupled to a second inverter.

3. The distributed propulsion system of claim 1, further comprising control circuitry, wherein the control circuitry is configured to control the plurality of switches.

4. The distributed propulsion system of claim 3, wherein the control circuitry is configured to:

control the plurality of switches to couple the first input to the first output via the first current path to cause the first AC current flowing from the first input to the first output to be regulated to a lower frequency than a frequency of the first AC current received at the first input to cause rotation of the first propulsor to slow.

5. The distributed propulsion system of claim 4, wherein the control circuitry is further configured to:

in response to determining that a rotational speed of the first propulsor is less than or equal to a threshold speed, control the plurality of switches to couple the second input to the second output via the second current path to cause the second AC current flowing from the second input to the second output to be regulated to a lower frequency than a frequency of the second AC current received at the second input to cause rotation of the second propulsor to slow.

6. The distributed propulsion system of claim 3, wherein the control circuitry is configured to:

control the plurality of switches to couple the first input to the first output via the first current path to cause the first AC current flowing from the first input to the first output to be regulated to a higher frequency than a frequency of the first AC current received at the first input to cause rotation of the first propulsor to quicken.

7. The distributed propulsion system of claim 6, wherein the regulated frequency causes the rotation of the first propulsor to increase from a first speed to a second speed, and wherein the control circuitry is further configured to:

while increasing the speed of the first propulsor, control the plurality of switches to couple the second input to the second output via the second current path to cause the second AC current flowing from the second input to the second output to be regulated to the same frequency as the regulated frequency of the AC current at the first output, such that a rotational speed of the second propulsor is equal to a rotational speed of the first propulsor.

8. The distributed propulsion system of claim 3, wherein:

in normal operation, the first input is electrically coupled to the first output via one of the first, second, third, or fourth current paths and the second input is electrically coupled to the second output via another one of the first, second, third, or fourth current paths;

the control circuitry is configured to determine whether a fault condition exists in the second generator or connecting component; and

in response to determining that fault condition is present, control the plurality of switches to couple the first input to the second output via one of the first, second, third, or fourth current paths.

9. The distributed propulsion system of claim 8, wherein the control circuitry is configured to control the plurality of switches to couple the first input to the second output via one of the first or second current paths.

10. The distributed propulsion system of claim 3, wherein the power regulation circuit is a first power regulation circuit and the plurality of switches are a first plurality of switches, the system further comprising:

a third propulsor and a fourth propulsor; and

a second power regulation circuit electrically coupled to the third propulsor via a third output, the fourth propulsor via a fourth output, the first generator via a third input, and the second generator via a fourth input, wherein the second power regulation circuit comprises;

a fifth current path comprising a third power electronics circuit,

a sixth current path comprising a fourth power electronics circuit,

a seventh current path that bypasses the third and fourth power electronics circuits,

an eighth current path that bypasses the third and fourth power electronics circuits, and

a second plurality of switches configured to selectively couple each respective input to a respective selected output to cause a respective current to flow from the respective input to the respective selected output via one of the fifth current path, the sixth current path, the seventh current path, or the eighth current path.

11. The distributed propulsion system of claim 10,

wherein the third power electronics circuit comprises a third rectifier electrically coupled to a third inverter, and

wherein the fourth power electronics circuit comprises a fourth rectifier electrically coupled to a fourth inverter.

12. The distributed propulsion system of claim 10, wherein the control circuitry is further configured to:

control the first plurality of switches to couple the first input to the first output via the first current path to cause the first AC current flowing from the first input to the first output to be regulated to a lower frequency than a frequency of the first AC current received at the first input to cause rotation of the first propulsor to slow from a first speed to a second speed, and

in response to determining that the second speed is less than or equal to a threshold speed, control the second plurality of switches to couple the third input to the third output via the fifth current path to cause the second AC current flowing from the third input to the third output to be regulated to a higher frequency than the first AC current received at the first input to cause rotation of the third propulsor to quicken.

13. The distributed propulsion system of claim 10, wherein the first and second propulsors are located on a side of a vessel opposite the third and fourth propulsors.

14. The distributed propulsion system of claim 1, further comprising:

a first electrical bus configured to provide the first AC current from the first generator to the power regulation circuit;

a second electrical bus configured to provide the second AC current from the second generator to the power regulation circuit;

a third propulsor selectively coupled to first electrical bus;

a fourth propulsor selectively coupled to second electrical bus; and

control circuitry configured to synchronize the fourth propulsor to the second generator by at least being configured to;

decouple the second electrical bus from the second generator;

couple the first current path to the fourth current path to cause the first AC current to flow from the first generator to the first power electronics circuit via the first electrical bus and first input;

regulate the first AC current to a frequency that is synchronized to the frequency of the second AC current generated by the second generator; and

couple the first current path to the fourth current path to cause the regulated first AC current to flow from the first power electronics circuit to the fourth propulsor via the second electrical bus.

15. The distributed propulsion system of claim 14, wherein the control circuitry is configured to couple the first current path to the fourth current path by closing at least one of the plurality of switches.

16. The distributed propulsion system of claim 15, wherein the control circuitry is further configured to synchronize the fourth propulsor to the second generator by at least being configured to:

electrically decouple the first propulsor from the power regulation circuit by opening at least a first switch of the plurality of switches; and

electrically decouple the second propulsor from the power regulation circuit by opening at least a second switch of the plurality of switches.

17. A method comprising:

receiving, by a power regulation circuit of a distributed propulsion system, a first AC current from a first generator of the distributed propulsion system via a first input of the power regulation circuit, wherein the power regulation circuit is electrically coupled to a first propulsor via a first output,

receiving, by the power regulation circuit, a second AC current from a second generator of the distributed propulsion system via a second input of the power regulation circuit, wherein the power regulation circuit is electrically coupled to a second propulsor via a second output,

controlling, by control circuitry of the distributed propulsion system, one or more of a plurality of switches of the power regulation circuit, to selectively couple each respective input to a respective selected output to cause a respective current to flow from the respective input to the respective selected output via one of a first current path, a second current path, a third current path, or a fourth current path,

wherein the first current path includes a first power electronics circuit, the second current path includes a second power electronics circuit, the third current path bypasses the first and second power electronics circuits, and the fourth current path bypasses the first and second power electronics circuits.

18. The method of claim 17,

wherein the first power electronics circuit comprises a first rectifier electrically coupled to a first inverter, and

wherein the second power electronics circuit comprises a second rectifier electrically coupled to a second inverter.

19. A system comprising:

a first propulsor and a second propulsor;

a first generator configured to generate a first AC current;

a second generator configured to generate a second AC current; and

a power regulation circuit electrically coupled to the first propulsor via a first output, the second propulsor via a second output, the first generator via a first input, and the second generator via a second input, wherein the power regulation circuit comprises;

a first current path comprising a first power electronics circuit,

a second current path comprising a second power electronics circuit,

a third current path that bypasses the first and second power electronics circuits,

a fourth current path that bypasses the first and second power electronics circuits, and

means for selectively coupling each respective input to a respective selected output to cause a respective current to flow from the respective input to the respective selected output via one of the first current path, the second current path, the third current path, or the fourth current path.

20. The system of claim 19,

wherein the first power electronics circuit comprises a first rectifier electrically coupled to a first inverter, and

wherein the second power electronics circuit comprises a second rectifier electrically coupled to a second inverter.