Core structure

• US 6,873,237 B2
• Filed: 04/18/2002
• Issued: 03/29/2005
• Est. Priority Date: 04/18/2002
• Status: Active Grant

• Current Assignee: MyPAQ Holdings Ltd. (Transpacific IP Group Limited)
• Original Assignee: Innovative Technology Licensing LLC
• Inventors: Sun, Jian, Chandrasekaran, Sriram, Mehrotra, Vivek
• Primary Examiner(s): Nguyen, Tuyen T.
• Application Number:
  US10/126,477
• Publication Number:
  US 20030197585A1
• Time in Patent Office: 1,076 Days
• Field of Search: 336/65, 336/83, 336/212, 336/214, 336/215, 336/216, 336/221, 336/233, 336/234, 336/170
• US Class Current: 336/83
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 3/08 made from powder powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06
• CPC Class Codes: H01F 30/06 characterised by the structure
• CPC Class Codes: H02M 7/043 using transformers or inductors only

Abstract

There is disclosed a core structure with a very low profile, high power density and lower losses. Higher core surface area and improved core utilization in terms of flux density are other desirable feature in the disclosed design. The disclosed design also allowed for a larger core area where the DC fluxes are added, thereby reducing the air-gap requirements in the cores derived from low saturation density materials such as ferrites. The cellular nature of the design can also be effectively employed in vertically packaged power converters and modules.

Claims

1. A core comprising:

a base having an outer edge and a top region,

a first post disposed on the top region of the base at the outer edge,

a second post disposed on the top region of the base at the outer edge,

a third post disposed on the top region of the base at the outer edge,

a fourth post disposed on the top region of the base at the outer edge,

a shared common center portion disposed on the base,

a top disposed on the posts and opposite the base,

wherein the first post and the center portion are separated on the base to thereby define a first window, the second post and the center portion are separated on the base to thereby define a second window, the third post and the center portion are separated on the base to thereby define a third window, the fourth post and the center portion are separated on the base to thereby define a fourth window, and the top and center portion are spaced apart to thereby define an air gap,

eight primary windings and eight secondary windings in an arrangement on the core, the arrangement defining four cells each comprising two primary windings and two secondary windings, and

a control circuit having an output connected to the primary windings, the control circuit having at least two phases, said phases being power transfer phases, in which current runs from the output in a first direction during a first power transfer phase and in the opposite direction during a second power transfer phase, two of the cells being powered by the control circuit during the first power transfer phase and the other two cells being powered by the control circuit during the second power transfer phase, said arrangement forming a power converter suitable for providing a load current to a load.

2. The core of claim 1, wherein the first post, the second post, the third post, the fourth post are disposed on the base in a rectangular matrix.

3. The core of claim 2, wherein the rectangular matrix is square.

4. The core of claim 1, wherein the base has a square shape and the posts are each disposed at a different corner of the square shape.

5. The core of claim 4, wherein the center portion has plural legs in a plus shape.

6. The core of claim 1, wherein the posts are disposed on the base in a symmetrical pattern.

7. The core of claim 1, wherein the windings have respective directions, and the directions provide for additive flux in the center portion when the windings are energized as inductors.

8. The core of claim 1, wherein the base, the posts and the center portion are an integrated unit.

9. The core of claim 1, wherein the base, the posts and the center portion are formed of a single material.

10. The core of claim 1, wherein the posts have a common height measured from the base, and the center portion has a height which is less than the common height of the posts.

11. The core of claim 1, wherein the posts have a common shape.

12. The core of claim 1, wherein the posts have a rectangular shape.

13. The core of claim 1, wherein each of said first, second, third and fourth posts has two of said primary windings and two of said secondary windings.

14. The core of claim 13, wherein the directions of said windings are arranged such that magnetic fluxes generated in said posts are additive in said common center portion.

15. The core of claim 13, wherein said control circuit is further arranged to have a freewheeling phase during which the currents in all of said primary windings are zero and the currents in the secondary windings of all four cells deliver said load current.

16. The core of claim 13, wherein said control circuit energizes said windings such that said power converter is a current doubler rectifier (CDR).

17. The core of claim 16, wherein said control circuit is further arranged to have a freewheeling phase during which the currents in all of said primary windings are zero and the currents in the secondary windings of all four cells deliver said load current.

18. The core of claim 17, wherein the control circuit energizes said windings such that said CDR has said first and second power transfer phases and a freewheeling phase, the load current provided by said CDR divided into four parallel paths during said power transfer phases when power is transferred across said core from said primary windings to said secondary windings, and into eight parallel paths during said freewheeling phase.

19. A current doubler rectifier (CDR), comprising:

a core structure, comprising;

a base having an outer edge and a top region,

a first post disposed on the top region of the base at the outer edge,

a second post disposed on the top region of the base at the outer edge,

a third post disposed on the top region of the base at the outer edge,

a fourth post disposed on the top region of the base at the outer edge,

a shared common center portion disposed on the base,

a top disposed on the posts and opposite the base,

wherein the first post and the center portion are separated on the base to thereby define a first window, the second post and the center portion are separated on the base to thereby define a second window, the third post and the center portion are separated on the base to thereby define a third window, the fourth post and the center portion are separated on the base to thereby define a fourth window, and the top and center portion are spaced apart to thereby define an air gap,

eight primary windings and eight secondary windings in an arrangement on the core, wherein each of said first, second, third and fourth posts has two of said primary windings and two of said secondary windings, the arrangement defining four cells each comprising two primary windings and two secondary windings, and

a control circuit having an output connected to the primary windings, the control circuit having first and second power transfer phases and a freewheeling phase, in which current runs from the output in a first direction during said first power transfer phase and in the opposite direction during said second power transfer phase and the currents in all of said primary windings are zero during said freewheeling phase, two of the cells being powered by the control circuit during the first power transfer phase and the other two cells being powered by the control circuit during the second power transfer phase,

said arrangement forming a CDR suitable for providing a load current to a load such that the load current provided by said CDR is divided into four parallel paths during said power transfer phases when power is transferred across said core from said primary to said secondary windings, and into eight parallel paths during said freewheeling phase when the currents in the secondary windings of all four cells deliver said load current.