Power distribution system and load management protocol therefor

• US 20060267406A1
• Filed: 05/25/2005
• Published: 11/30/2006
• Est. Priority Date: 05/25/2005
• Status: Active Grant

• Current Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Mehrer, Michael E., Vaziri, Massoud, Spencer, John P.
• Granted Patent: US 7,622,821 B2
• Time in Patent Office: Days
• US Class Current: 307/9.100
• CPC Class Codes: B64D 2221/00 Electric power distribution systems onboard aircraft
• CPC Class Codes: B64D 41/00 Power installations for auxiliary purposes
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

An Auxiliary Power System includes an APU controller and an aircraft load controller which include an APU load capacity algorithm which provides an uncomplicated and robust method of APU load control. The APU load capacity algorithm defines three load zones: a continuous APU load capacity zone (zone A); a time controlled zone (zone B); and a fault zone (zone C). Each zone is related to altitude to the service ceiling of the APU to provides consistent APU load capacity that addresses APU performance variation and deterioration effects to an end of the APU useful life.

Claims

1. A power distribution system for an aircraft comprising:

a power source;

a controller in communication with said power source; and

an aircraft load controller in communication with said power source controller and a multitude of loads, one of said power source controller and said aircraft load controller including an instruction set with power source load capacity algorithm and said aircraft load controller operable to selectively shed one or more of said loads in response to said power source load capacity algorithm.

2. The power distribution system of claim 1, wherein said power source is an auxiliary power unit (APU).

3. The power distribution system as recited in claim 2, wherein said APU generates only an electrical output.

4. The power distribution system as recited in claim 1, wherein said power source load capacity algorithm defines a multitude of zones, said multitude of zones include a continuous load capacity zone;

a time controlled zone above said continuous load capacity zone; and

a fault zone above said time controlled zone.

5. The power distribution system as recited in claim 4, wherein said continuous load capacity zone provides 100 percent of power source load capacity at sea level.

7. The method of claim 1, wherein said power source is an auxiliary power unit (APU).

6. A method of controlling a power distribution system having a power source comprising the steps of:

(1) determining whether the power source is operating within a predefined continuous load capacity zone;

(2) determining whether the power source is operating within a predefined frequent over-load zone above the predefined continuous load capacity zone for a predetermined time period; and

(3) recording a duration of power source operation which exceeds the predetermined time period of said step (2).

8. A method as recited in claim 6, wherein said step (3) further comprises:

(a) generating a fault condition when the time of power source operation exceeds the predetermined time period.

9. A method as recited in claim 6, further comprising the steps of:

(4) determining whether the power source is operating within a predefined fault load zone above the predefined frequent over-load zone; and

(5) recording a time of power source operation within the predefined fault load zone of said step (4).

10. A method as recited in claim 6, further comprising the steps of:

(4) determining that the power source is operating within a predefined fault load zone above the predefined frequent over-load zone;

(5) determining that the aircraft is on the ground; and

(6) shutting down the power source in response to said step (5).

11. A method as recited in claim 10, further comprising the step of:

(7) setting a fault condition.

12. A method as recited in claim 10, further comprising the steps of:

(7) determining that the power source is operating within a zone above the predefined fault load zone;

(8) determining that the aircraft is on the ground; and

(9) shutting down the power source in response to said step (7).

13. A method as recited in claim 6, further comprising the steps of:

(4) determining that the power source is operating within a predefined fault load zone above the predefined frequent over-load zone;

(5) determining that the aircraft is in the air; and

(6) recording a time of power source operation within the predefined fault load zone of said step (4).

14. A method as recited in claim 13, further comprising the step of:

(7) setting a fault condition.

15. A method as recited in claim 13, further comprising the steps of:

(7) determining that the power source is operating within a zone above the predefined fault load zone;

(8) determining that the aircraft is in the air; and

(9) recording a time of power source operation within the zone of said step (7).

16. A method of controlling a power distribution system having a power source comprising the steps of:

(1) determining that the power source is operating within a predefined continuous load capacity zone;

(2) determining that the power source is operating within a predefined frequent overload zone above the predefined continuous load capacity zone;

(3) shedding a load in response to said step (2) such that the power source operates in the predefined continuous load capacity zone.

17. The method of claim 16, wherein said power source is an auxiliary power unit (APU).

18. A method as recited in claim 16, further comprising the steps of:

(4) communicating with an aircraft load control system such that said aircraft load control system performs said step (2).