Magnetic device formed with U-shaped core pieces and power converter employing the same

• US 9,019,061 B2
• Filed: 03/31/2010
• Issued: 04/28/2015
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Power Systems Technologies Company Limited (Flex, Ltd.)
• Original Assignee: Power Systems Technologies Company Limited (Flex, Ltd.)
• Inventors: Chandrasekaran, Sriram
• Primary Examiner(s): Lian, Mangtin
• Application Number:
  US12/751,650
• Publication Number:
  US 20100254168A1
• Time in Patent Office: 1,854 Days
• Field of Search: 336/212, 336220-222, 336/170, 336/233, 336/184, 336/178, 296/021, 296/05, 296/06
• US Class Current: 336/212
• CPC Class Codes: H01F 2038/026 non-linear inductive arrangements for converters, e.g. with additional windings
• CPC Class Codes: H01F 27/263 Fastening parts of the core together
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 3/12 Magnetic shunt paths
• CPC Class Codes: H01F 3/14 Constrictions; Gaps, e.g. air-gaps in magnetic shunt paths H01F3/12
• CPC Class Codes: H01F 30/06 characterised by the structure
• CPC Class Codes: H01F 37/00 Fixed inductances not covered by group H01F17/00
• CPC Class Codes: H01F 41/02 for manufacturing cores, coils, or magnets H01F41/14 takes precedence; for dynamo-electric machines H02K15/00
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: H02M 3/1586 switched with a phase shift, i.e. interleaved
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

A magnetic device formed with U-shaped core pieces employable in a power converter, and a method of forming the same. In one embodiment, the magnetic device includes a rectilinear core piece formed of a magnetic material, and first and second U-shaped core pieces positioned on the rectilinear core piece. The magnetic device also includes first and second conductive windings formed about the first and second U-shaped core pieces, respectively.

Claims

1. A magnetic device, comprising:

a rectilinear core piece formed of a magnetic material;

first and second U-shaped core pieces with a bottom surface of ends thereof positioned on a common surface of said rectilinear core piece, a relative permeability of said rectilinear core piece being substantially lower than a relative permeability of said first and second U-shaped core pieces;

first and second conductive windings formed about said first and second U-shaped core pieces, respectively; and

a third conductive winding formed about said rectilinear core piece and electrically coupled to said first and second conductive windings at a common terminal.

2. The magnetic device as recited in claim 1 wherein said first and second conductive windings are formed over substantially an entire curved length of said first and second U-shaped core pieces, respectively.

3. The magnetic device as recited in claim 1 wherein said first and second U-shaped core pieces are formed with a soft ferrite.

4. The magnetic device as recited in claim 1 further comprising a nonmagnetic spacer positioned between said bottom surface of said ends of at least one of said first and second U-shaped core pieces and said common surface of said rectilinear core piece.

5. The magnetic device as recited in claim 1 wherein said first and second U-shaped core pieces are separated by a portion of said common surface of said rectilinear core piece.

6. The magnetic device as recited in claim 1 wherein said third conductive winding is formed as a staple.

7. The magnetic device as recited in claim 1 wherein said first and second conductive windings are formed as a single layer about said first and second U-shaped core pieces, respectively.

8. The magnetic device as recited in claim 1 wherein said rectilinear core piece is formed with a distributed gap.

9. The magnetic device as recited in claim 1 wherein said first and second conductive windings are first and second secondary windings and said third conductive winding is a common winding coupled thereto.

10. The magnetic device as recited in claim 1 wherein said first and the second U-shaped core pieces are each formed as a portion of a toroidal core.

11. A method of forming a magnetic device, comprising:

providing a rectilinear core piece of a magnetic material;

positioning a bottom surface of ends of first and second U-shaped core pieces on a common surface of said rectilinear core piece, a relative permeability of said rectilinear core piece being substantially lower than a relative permeability of said first and second U-shaped core pieces;

forming first and second conductive windings about said first and second U-shaped core pieces, respectively; and

forming a third conductive winding about said rectilinear core piece and electrically coupled to said first and second conductive windings at a common terminal.

12. The method as recited in claim 11 wherein said first and second conductive windings are formed over substantially an entire curved length of said first and second U-shaped core pieces, respectively.

13. The method as recited in claim 11 wherein said first and second U-shaped core pieces formed with a soft ferrite.

14. The method as recited in claim 11 further comprising positioning a nonmagnetic spacer between said bottom surface of said ends of at least one of said first and second U-shaped core pieces and said common surface of said rectilinear core piece.

15. The method as recited in claim 11 wherein said first and second U-shaped core pieces are separated by a portion of said common surface of said rectilinear core piece.

16. The method as recited in claim 11 wherein said third conductive winding is formed as a staple.

17. The method as recited in claim 11 wherein said first and second conductive windings are formed as a single layer about said first and second U-shaped core pieces, respectively.

18. The method as recited in claim 11 wherein said rectilinear core piece is formed with a distributed gap.

19. The method as recited in claim 11 wherein said first and second conductive windings are first and second secondary windings and said third conductive winding is a common winding coupled thereto.

20. The method as recited in claim 11 wherein said first and the second U-shaped core pieces are each formed as a portion of a toroidal core.