ELECTRICAL SYSTEM AND ELECTRICAL ACCUMULATOR FOR ELECTRICAL ACTUATION AND RELATED METHODS

• US 20090302153A1
• Filed: 06/10/2008
• Published: 12/10/2009
• Est. Priority Date: 06/10/2008
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Matasso, Anthony F., Iden, Steven M.
• Granted Patent: US 8,789,791 B2
• Time in Patent Office: Days
• US Class Current: 244/99.200
• CPC Class Codes: B64C 13/504 using electro-hydrostatic actuators [EHA's]
• CPC Class Codes: B64D 2221/00 Electric power distribution systems onboard aircraft
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

An electrical system for driving flight control actuators, electrical accumulator, and methods for managing electrical power for an aircraft electrical system and methods of retrofitting an aircraft electrical system with an electrical accumulator are provided. The electrical system can include a bidirectional accumulator positioned in electrical communication with the plurality of flight control actuators to absorb excess electrical power regenerated by the plurality of flight control actuators and to provide supplemental power to the plurality of flight control actuators to thereby satisfy transient power requirements.

Claims

1. An aircraft electrical system for an aircraft having a plurality of electrically actuated aerodynamic control surfaces, comprising:

a plurality of electrically powered aircraft flight control actuators each including an electric motor operably coupled thereto and each positioned to move one of the plurality of aerodynamic control surfaces; and

a bidirectional electrical accumulator positioned in electrical communication with the plurality of flight control actuators to absorb excess electrical power regenerated by the plurality of flight control actuators and to provide supplemental power to the plurality of flight control actuators to thereby satisfy transient power requirements.

2. The aircraft electrical system as defined in claim 1, wherein the electrical system includes an aircraft engine driven generator or fuel cell to provide continuous power, and wherein the bidirectional electrical accumulator is positioned to absorb transient voltages beyond that capable of being absorbed under maximum continuous conditions by the aircraft electrical system without a regenerative absorption device and to satisfy transient power requirements beyond that capable of being supplied under maximum continuous conditions by the engine driven generator.

3. The aircraft electrical system as defined in claim 1, wherein the bidirectional electrical accumulator includes a first energy storage device comprising an ultracapacitor having a minimum rating of 25 kilowatts, and a second energy storage device comprising a lithium ion battery having a minimum rating of 2.5 amp-hours.

4. The aircraft electrical system as defined in claim 1, wherein the bidirectional electrical accumulator includes:

a first energy storage device positioned to absorb excess electrical power regenerated by the plurality of flight control actuators and to provide supplemental power to the plurality of control actuators to thereby satisfy transient power requirements; and

a second energy storage device positioned to redundantly absorb peak excess electrical power regenerated by the plurality of control actuators when not sufficiently absorbed by the first energy storage device and to redundantly provide supplemental power to the plurality of control actuators when not sufficiently provided by the first energy storage device.

5. The aircraft electrical system as defined in claim 1, wherein the plurality of flight control actuators is a first plurality of flight control actuators, wherein the aircraft electrical system further comprises a second plurality of electrically actuated vehicle flight control actuators each including an electrical motor operably coupled thereto, and wherein the bidirectional electrical accumulator includes a first energy storage device and a second energy storage device:

the first energy storage device positioned to absorb excess electrical power regenerated by the first plurality of flight control actuators and to provide supplemental power to the first plurality of control actuators to thereby satisfy transient power requirements, and to redundantly absorb peak excess electrical power regenerated by the second plurality of flight control actuators when not sufficiently absorbed by the second energy storage device and to redundantly provide supplemental power to the second plurality of flight control actuators when not sufficiently provided by the second energy storage device; and

the second energy storage device positioned to absorb excess electrical power regenerated by the second plurality of flight control actuators and to provide supplemental power to the second plurality of control actuators to thereby satisfy transient power requirements, and positioned to redundantly absorb peak excess electrical power regenerated by the first plurality of control actuators when not sufficiently absorbed by the first energy storage device and to redundantly provide supplemental power to the first plurality of control actuators when not sufficiently provided by the first energy storage device.

6. A vehicle electrical system, comprising:

a plurality of electrically powered vehicle control actuators each including an electric motor operably coupled thereto; and

a bidirectional electrical accumulator positioned in electrical communication with the plurality of control actuators to provide power thereto and to receive power therefrom, the bidirectional electrical accumulator including;

a first energy storage device positioned to absorb excess electrical power regenerated by the plurality of control actuators and to provide supplemental power to the plurality of control actuators, and

a second energy storage device positioned to redundantly absorb peak excess electrical power regenerated by the plurality of control actuators and to redundantly provide supplemental power to the plurality of control actuators.

7. The vehicle electrical system as defined in claim 6, wherein the vehicle is an aircraft having an engine driven generator, and wherein the first energy storage device is positioned to absorb transient voltages beyond that capable of being absorbed under maximum continuous conditions by the vehicle electrical system without a regenerative absorption device and to satisfy transient power requirements beyond that capable of being supplied under maximum continuous conditions by the engine driven generator.

8. The vehicle electrical system as defined in claim 6, wherein the first energy storage device comprises an ultracapacitor having a minimum rating of 25 kilowatts, and wherein the second energy storage device comprises a lithium ion battery having a minimum rating of 2.5 amp-hours.

9. The vehicle electrical system as defined in claim 6,

wherein the vehicle is an aircraft having a plurality of aerodynamic control surfaces;

wherein the plurality of vehicle control actuators is a plurality of aircraft flight control actuators each positioned to move one of the plurality of aerodynamic control surfaces;

wherein the vehicle electrical system further comprises;

a first vehicle direct current (DC) bus positioned in electrical communication with the plurality of flight control actuators, and

a second vehicle DC bus positioned in electrical communication with the plurality of flight control actuators;

wherein the first energy storage device is in electrical communication with the first vehicle DC bus to provide power to each of the plurality of flight control actuators and to receive power regenerated by the plurality of flight control actuators;

wherein the second energy storage device is in electrical communication with the second vehicle DC bus to redundantly provide power to each of the plurality of flight control actuators and to redundantly receive power regenerated by the plurality of flight control actuators; and

wherein the bidirectional electrical accumulator is positioned to absorb regenerative power for the first DC bus sufficient to maintain bus voltage within maximum continuous bus ratings thereof and to absorb regenerative power for the second DC bus sufficient to maintain bus voltage within maximum continuous bus ratings thereof.

10. The vehicle electrical system as defined in claim 9, wherein the first energy storage device comprises a capacitor having a minimum rating of 25 kilowatts, and wherein the second energy storage device comprises a capacitor having a minimum rating of 25 kilowatts and a battery having a minimum rating of 2.5 amp-hours.

11. The vehicle electrical system as defined in claim 9, wherein the bidirectional electrical actuator unit includes:

a first DC-DC power converter in communication with the first vehicle DC bus and the first energy storage device to match and regulate voltage between the capacitor and the first vehicle DC bus, the capacitor in combination with the first DC-DC power converter positioned to absorb the regenerative power sufficient to maintain bus voltage of the first vehicle DC bus within maximum continuous bus ratings; and

a second DC-DC power converter in communication with the second vehicle DC bus and the second energy storage device to match and regulate voltage between the battery and the second vehicle DC bus, the battery in combination with the second DC-DC power converter positioned to absorb the regenerative power sufficient to maintain bus voltage of the second vehicle DC bus within maximum continuous bus ratings.

12. The vehicle electrical system as defined in claim 9,

wherein the plurality of aircraft flight control actuators is a first plurality of flight control actuators;

wherein the system further comprises a second plurality of electrically actuated vehicle flight control actuators each including an electrical motor operably coupled thereto;

wherein the second energy storage device and the second vehicle DC bus are positioned in electrical communication with the second plurality of flight control actuators to provide power to each of the second plurality of flight control actuators and to receive power regenerated by the second plurality of flight control actuators; and

wherein the first energy storage device and the first vehicle DC bus are positioned in electrical communication with the second plurality of flight control actuators to redundantly provide power to each of the second plurality of flight control actuators and to redundantly receive power regenerated by the second plurality of flight control actuators.

13. A method of managing electrical power for an aircraft electrical system of an aircraft comprising an aircraft flight control system including electrically powered flight control actuators, the method comprising the step of:

absorbing regenerative power produced by a plurality of flight control actuators each having an electric motor operably coupled thereto, the absorbing performed by a bidirectional electrical accumulator electrically coupled to the plurality of flight control actuators.

14. The method as defined in claim 13, wherein the step of absorbing regenerative power includes absorbing transient voltages beyond that capable of being absorbed under maximum continuous conditions by the aircraft electrical system without a regenerative absorption device coupled thereto.

15. The method as defined in claim 14, wherein the aircraft electrical system includes an engine driven generator or a fuel cell to provide continuous aircraft electrical power, and wherein the method further comprises the step of satisfying transient power requirements beyond that capable of being supplied under maximum continuous conditions by the engine driven generator or fuel cell, the satisfying transient power requirements performed by the bidirectional electrical accumulator.

16. The method as defined in claim 13, wherein the aircraft electrical system includes an engine driven generator, the method further comprising the steps of:

providing average continuous power by the engine driven generator to thereby satisfy average continuous power requirements;

providing supplemental power to the plurality of flight control actuators by the bidirectional electrical accumulator to thereby satisfy transient power requirements; and

charging the bidirectional electrical accumulator by the engine driven generator when not encountering the transient power requirements to thereby maintain the bidirectional electrical accumulator at a minimum power level.

17. The method as defined in claim 16, wherein the aircraft electrical system includes at least one aircraft flight control actuation system bus electrically coupled to the plurality of flight control actuators and to the bidirectional electrical accumulator, and wherein the electrical bidirectional accumulator comprises at least one energy storage device and a corresponding at least one bidirectional power controller electrically coupled with the at least one energy storage device and to the at least one aircraft flight control actuation system bus, the method further comprising the step of:

managing voltage between the at least one energy storage device and the at least one aircraft flight control actuation system bus by the at least one bidirectional power controller.

18. The method as defined in claim 13,

wherein the plurality of flight control actuators is a first plurality of flight control actuators;

wherein the bidirectional electrical accumulator includes;

a first energy storage device electrically coupled to the first plurality of flight control actuators and redundantly coupled to a second plurality of flight control actuators, and

a second energy storage device electrically coupled to the second plurality of flight control actuators and redundantly coupled to the first plurality of flight control actuators;

wherein the step of absorbing regenerative power includes the first energy storage device absorbing excess electrical power regenerated by the first plurality of flight control actuators, and absorbing excess electrical power regenerated by the second plurality of flight control actuators when not sufficiently absorbed by the second energy storage device;

wherein the method further comprises the steps of;

the second energy storage device absorbing excess electrical power regenerated by the second plurality of flight control actuators and excess electrical power regenerated by the first plurality of flight control actuators when not sufficiently absorbed by the first energy storage device,

the first energy storage device providing supplemental power to the first plurality of flight control actuators, and supplemental power to the second plurality of flight control actuators when not sufficiently provided by the second energy storage device, and

the second energy storage device providing supplemental power to the second plurality of flight control actuators, and supplemental power to the first plurality of flight control actuators when not sufficiently provided by the first energy storage device.

19. The method as defined in claim 13,

wherein the plurality of flight control actuators is a first plurality of flight control actuators;

wherein the aircraft electrical system includes;

an engine driven generator,

a first aircraft flight control actuation system bus electrically coupled to the first plurality of flight control actuators, and

a second aircraft flight control actuation system bus electrically coupled to a second plurality of flight control actuators;

wherein the electrical bidirectional accumulator further comprises;

a first energy storage device positioned to absorb excess electrical power regenerated by the first plurality of flight control actuators and to provide supplemental power to the first plurality of flight control actuators,

a second energy storage device positioned to absorb excess electrical power regenerated by the second plurality of flight control actuators and to provide supplemental power to the second plurality of flight control actuators,

a first bidirectional power controller electrically coupled to the first energy storage device and the first aircraft flight control actuation system bus, and

a second bidirectional power controller electrically coupled to the second energy storage device and the second aircraft flight control actuation system bus; and

wherein the method further comprises the steps of;

managing voltage between the first energy storage device and the first aircraft flight control actuation system bus by the first bidirectional power controller, and

managing voltage between the second energy storage device and the second aircraft flight control actuation system bus by the second bidirectional power controller.

20. The method as defined in claim 19, further comprising the steps of:

providing average continuous power to the plurality of flight control actuators by the engine driven generator to thereby satisfy average continuous power requirements by the engine driven generator;

providing supplemental power to the first plurality of flight control actuators by the first energy storage device to thereby satisfy transient power requirements thereof;

providing supplemental power to the second plurality of flight control actuators by the second energy storage device to thereby satisfy transient power requirements thereof;

charging the first energy storage device by the engine driven generator when not encountering the transient power requirements to thereby maintain the bidirectional electrical accumulator at a minimum power level; and

charging the second energy storage device by the engine driven generator when not encountering the transient power requirements to thereby maintain the bidirectional electrical accumulator at a minimum power level.

21. The vehicle electrical system as defined in claim 20, wherein the first energy storage device comprises a capacitor having a minimum rating of 25 kilowatts, and wherein the second energy storage device comprises a battery having a minimum rating of 2.5 amp-hours.

22. A method of retrofitting an aircraft electrical system of an aircraft including an engine driven generator or fuel cell defining an aircraft continuous power source and electrically powered flight control actuators, with a bidirectional electrical accumulator adapted to provide high pulse power thereto and to receive regenerative power therefrom, the method comprising the steps of:

removing a regenerative resistor positioned in electrical communication with a plurality of flight control actuators each having an electric motor operably coupled thereto, to absorb transient voltages beyond that capable of being absorbed under maximum continuous conditions by the aircraft electrical system without a regenerative absorption device; and

installing a bidirectional electrical accumulator in electrical communication with the plurality of flight control actuators to absorb transient voltages beyond that capable of being absorbed under maximum continuous conditions by the aircraft electrical system without a regenerative absorption device installed therein.

23. The method as defined in claim 22, wherein the bidirectional electrical accumulator when installed functions to satisfy transient power requirements beyond that capable of being supplied under maximum continuous conditions by the aircraft continuous power source.

24. The method as defined in claim 23, wherein the aircraft continuous power source is a second engine driven generator, and wherein the method further comprises the step of:

removing a first engine driven generator; and

installing the second engine driven generator having a weight and capacity substantially below that of the first engine driven generator.

25. The method as defined in claim 22,

wherein the plurality of flight control actuators is a first plurality of flight control actuators;

wherein the bidirectional electrical accumulator includes a first energy storage device positioned to absorb excess electrical power regenerated by the first plurality of flight control actuators and to provide supplemental power to the first plurality of flight control actuators, and to redundantly absorb peak excess electrical power regenerated by a second plurality of flight control actuators and to redundantly provide peak supplemental power to the second plurality of flight control actuators; and

wherein the bidirectional electrical accumulator includes a second energy storage device positioned to absorb excess electrical power regenerated by the second plurality of flight control actuators and to provide supplemental power to the second plurality of flight control actuators, and to redundantly absorb peak excess electrical power regenerated by a first plurality of flight control actuators and to redundantly provide peak supplemental power to the first plurality of flight control actuators.

26. The method as defined in claim 25, wherein the first energy storage device comprises a capacitor having a minimum rating of 25 kilowatts, and wherein the second energy storage device comprises a battery having a minimum rating of 2.5 amp-hours.