METHOD AND APPARATUS FOR ELECTRICAL BUS CENTERING

• US 20100302823A1
• Filed: 05/29/2009
• Published: 12/02/2010
• Est. Priority Date: 05/29/2009
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Systems, LLC (General Electric Company)
• Inventors: Radun, Arthur Vorwerk, Huang, Hao, Zhou, Rui, Karipides, David Dimitri
• Granted Patent: US 8,050,069 B2
• Time in Patent Office: Days
• US Class Current: 363/127
• CPC Class Codes: H02M 1/00 Details of apparatus for conversion
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters

Abstract

A bus centering device for use in an aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground is described. The device includes a central node, a first and second switching component configured to couple the central node to the positive rail and the negative rail for a first and second predetermined duty cycle, respectively. The device includes an inductive component coupled between the central node and ground, and is configured to maintain a voltage at the central node substantially equal to ground, wherein a voltage between the positive rail and the central node is maintained substantially equal to a voltage between the negative rail and the central node. The device includes a first and second current limiting device configured to maintain a continuity of current from the inductive component when the first and second switching components are turned off.

Claims

1. A bus centering device for use in an aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground, said device comprising:

a central node;

a first switching component configured to couple the central node to the positive bus rail for a first predetermined duty cycle;

a second switching component configured to couple the central node to the negative bus rail for a second predetermined duty cycle;

an inductive component coupled between the central node and ground, said inductive component configured to maintain a voltage at the central node substantially equal to ground potential, wherein a voltage between the positive bus rail and the central node is maintained substantially equal to a voltage between the negative bus rail and the central node;

a first current limiting device coupled to said first switching component and said inductive component, said first current limiting device configured to maintain a continuity of current from said inductive component when said first switching component is turned off; and

a second current limiting device coupled to said second switching component and said inductive component, said second current limiting device configured to maintain a continuity of current from said inductive component when said second switching component is turned off.

2. A device in accordance with claim 1, wherein said first switching component is switched at a first duty cycle of approximately 50% and said second switching component is switched at a second duty cycle of approximately 50%, the switching of said second switching component is phase-delayed by approximately 180 degrees from the switching of said first switching component.

3. A device in accordance with claim 1, wherein said device comprises a third, fourth, fifth, and sixth switching component.

4. A device in accordance with claim 3, wherein said third switching component is switched at a third duty cycle of approximately 50% and said fourth switching component is switched at a fourth duty cycle of approximately 50%, the switching of said fourth switching component is phase-delayed by approximately 180 degrees from the switching of said third switching component.

5. A device in accordance with claim 3, wherein said fifth switching component is switched at a fifth duty cycle of approximately 50% and said sixth switching component is switched at a sixth duty cycle of approximately 50%, the switching of said sixth switching component is phase-delayed by approximately 180 degrees from the switching of said fifth switching component.

6. A device in accordance with claim 1, wherein said inductive component comprises a three leg interphase transformer.

7. An aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground, said system comprising:

a power source;

a load; and

a bus centering device comprising;

a central node;

a first switching component configured to couple the central node to the positive bus rail for a first predetermined duty cycle;

a second switching component configured to couple the central node to the negative bus rail for a second predetermined duty cycle;

an inductive component coupled between the central node and ground, said inductive component configured to maintain a voltage at the central node substantially equal to ground potential, wherein a voltage between the positive bus rail and the central node is maintained substantially equal to a voltage between the negative bus rail and the central node;

a first current limiting device coupled to said first switching component and said inductive component, said first current limiting device configured to maintain a continuity of current from said inductive component when said first switching component is turned off; and

a second current limiting device coupled to said second switching component and said inductive component, said second current limiting device configured to maintain a continuity of current from said inductive component when said second switching component is turned off.

8. A system in accordance with claim 7, wherein said first switching component is switched at a first duty cycle of approximately 50% and said second switching component is switched at a second duty cycle of approximately 50%, the switching of said second switching component is phase-delayed by approximately 180 degrees from the switching of said first switching component.

9. A system in accordance with claim 7, wherein said device comprises a third, fourth, fifth, and sixth switching component.

10. A system in accordance with claim 9, wherein said third switching component is switched at a third duty cycle of approximately 50% and said fourth switching component is switched at a fourth duty cycle of approximately 50%, the switching of said fourth switching component is phase-delayed by approximately 180 degrees from the switching of said third switching component.

11. A system in accordance with claim 9, wherein said fifth switching component is switched at a fifth duty cycle of approximately 50% and said sixth switching component is switched at a sixth duty cycle of approximately 50%, the switching of said sixth switching component is phase-delayed by approximately 180 degrees from the switching of said fifth switching component.

12. A system in accordance with claim 7, wherein said inductive component comprises a three leg interphase transformer.

13. A system in accordance with claim 12, wherein said inductive component further comprises an inductor that is coupled to said three leg interphase transformer.

14. A method for centering an aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground, said method comprising:

providing a power source and a load that is coupled to the power source;

coupling a bus centering device to the positive bus rail, the negative bus rail, and the ground, the bus centering device includes;

a central node;

a first switching component, a second switching component, and an inductive component, the inductive component is coupled between the central node and ground;

coupling the central node to the positive bus rail for a first predetermined duty cycle;

coupling the central node to the negative bus rail for a second predetermined duty cycle; and

maintaining a voltage at the central node substantially equal to ground potential, wherein a voltage between the positive bus rail and the central node is maintained substantially equal to a voltage between the negative bus rail and the central node.

15. A method in accordance with claim 14, wherein the method further includes switching the first switching component at a first duty cycle of approximately 50% and switching the second switching component at a second duty cycle of approximately 50%, wherein the switching of the second switching component is phase-delayed by approximately 180 degrees from the switching of the first switching component.

16. A method in accordance with claim 14, wherein the method further includes coupling a third, fourth, fifth, and sixth switching component to at least one of the first input terminal and the second input terminal.

17. A method in accordance with claim 16, wherein the method further includes switching the third switching component at a third duty cycle of approximately 50% and switching the fourth switching component at a fourth duty cycle of approximately 50%, wherein the switching of the fourth switching component is phase-delayed by approximately 180 degrees from the switching of the third switching component.

18. A method in accordance with claim 16, wherein the method further includes switching the fifth switching component at a fifth duty cycle of approximately 50% and switching the sixth switching component at a sixth duty cycle of approximately 50%, wherein the switching of the sixth switching component is phase-delayed by approximately 180 degrees from the switching of the fifth switching component.

19. A method in accordance with claim 14, wherein the method further includes coupling a three leg interphase transformer to the first switching component and to the second switching component.

20. A method in accordance with claim 19, wherein the method further includes coupling an inductor to the three leg interphase transformer.