Transformer core

• US 6,809,620 B2
• Filed: 11/18/2002
• Issued: 10/26/2004
• Est. Priority Date: 02/06/2000
• Status: Expired due to Fees

• Current Assignee: Hexaformer AB
• Original Assignee: Höglund, Lennart
• Inventors: Höglund, Lennart
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US10/203,027
• Publication Number:
  US 20030090355A1
• Time in Patent Office: 708 Days
• Field of Search: 336/5, 336/212, 336/213, 336/234, 336/83, 336/200, 336/214, 336/215, 336/223, 336/232, 336/60, 296/05, 296/06
• US Class Current: 336/5
• CPC Class Codes: H01F 27/25 made from strips or ribbons H01F27/26 takes precedence
• CPC Class Codes: H01F 3/06 made from wires
• CPC Class Codes: H01F 41/0213 Manufacturing of magnetic circuits made from strip(s) or ribbon(s) magnetic cores made by winding a ribbon H01F27/25

Abstract

A transformer or inductor core of magnetic material has three legs (6, 8, 10) interconnected by yokes. The core comprises loops (12, 14, 16) of wires and/or strips of magnetic material, wherein each of the loops makes up part of two of the legs. Loops making up part of two different leg portions are interleaved in a common leg portion. This provides for mechanical stability and good magnetic properties for the core.

Claims

1. A core of magnetic material having a first, a second, and a third leg portion and a first and a second yoke portion, said core comprising:

loops of wires and/or strips of magnetic material;

each of said loops making up part of two of said leg portions;

wherein loops making up part of two different leg portions are interleaved in a common leg portion of said leg portions,

wherein each of said loops comprises a plurality of layers of wires and/or strips of magnetic material, and

wherein each of said layers comprises a plurality of wires and/or strips.

2. The core according to claim 1, wherein said leg portions are provided in a triangular pattern.

3. The core according to claim 1, wherein said leg portions are provided in a row.

4. The core according to claim 1, wherein said magnetic material is an amorphous material.

5. The core according to claim 1, wherein said leg portions have an essentially circular cross-sectional area.

6. The core according to claim 1, wherein said leg portions have an essentially elliptic cross-sectional area.

7. The core according to claim 1, wherein said leg portions comprise a magnetic composite material.

8. The core according to claim 1, wherein a single wire or strip is used in several loops.

9. A three-phase transformer having a core of magnetic material with a first, a second, and a third leg interconnected by a first and a second yoke, and primary and secondary windings wound around said legs, characterized in that said core is a core according to claim 1.

10. The core according to claim 1, wherein each of said layers comprises a plurality of strips, each of said strips being offset from adjacent strips.

11. The core according to claim 10, wherein the strips are of constant width.

12. The core according to claim 1, wherein each of said layers comprises a plurality of wires.

13. The core according to claim 12, wherein the wires have a square cross-sectional area.

14. The core according to claim 1, wherein all of said loops have one common leg portion.

15. A single-phase transformer having a core of magnetic material with a first, a second, and a third leg interconnected by a first and a second yoke, and primary and secondary windings wound around one of said legs, wherein said core is a core according to claim 14.

16. The core according to claim 1, wherein each of said legs comprises a portion of non-conductive material.

17. A three-phase inductor having a core of magnetic material with a first, a second, and a third leg interconnected by a first and a second yoke, and windings wound around said legs, characterized in that said core is a core according to claim 16.

18. A method of manufacturing a core of magnetic material having a first, a second, and a third leg portion and a first and a second yoke portion, said method comprising the following steps:

a) winding a first loop of wires and/or strips of magnetic material, said first loop making up part of said first and second leg portions;

b) winding a second loop of wires and/or strips of magnetic material, said second loop making up part of said second and third leg portions;

c) winding a third loop of wires and/or strips of magnetic material, said third loop making up part of said third and first leg portions;

d) repeating steps a)-c) until final cross-sectional shapes of said leg portions are obtained,

wherein loops making up part of two different leg portions are interleaved in a common leg portion of said leg portions,

wherein each of said loops comprises a plurality of layers of wires and/or strips of magnetic material, and

wherein each of said layers comprises a plurality of wires and/or strips.

19. The method according to claim 18, wherein said loops are wound separately.

20. The method according to claim 19, wherein the loops are wound on stands with conical cross section.