Patent EA-004491-B1 (EA)
Title: Transformer core
IPC: H01F27/25
Filed: 2001-02-06
Abstract: 1. A core of magnetic material having a first (6; 6'; 106; 206; 306), a second (8; 8'; 108; 208; 308), and a third (10; 10'; 110; 210; 310) leg portions and a first (2a-2c; 102a-102c; 202a-202c) and a second (4a-4c; 104a-104c; 204a-204c) yoke portion, said core comprising: -loops (12; 14; 16; 12'; 14'; 16'; 112; 114; 116; 213; 214; 216) of wires and/or strips of magnetic material; -each of said loops making up part of two of leg portions, characterized in that -loops making up part of two different leg portions are interleaved in a common leg portion of said leg portions. 2. The core according to claim 1, wherein each of said loops comprises a plurality of layers of wires and/or strips of magnetic material. 3. The core according to claim 2, wherein each of said layers comprises a plurality of strips (12a-12e), preferably strips of constant width, each of said strips being offset from adjacent strips. 4. The core according to claim 2, wherein each or said layers comprises a plurality of wires (112a), preferably wires with a square cross-sectional area. 5. The core according to any one of claims 1-4, wherein said leg portions (6, 8, 10, 106, 108, 110) are provided in a triangular pattern. 6. The core according to any one of claims 1-4, wherein said leg portions (206, 208, 210) are provided in a row. 7. The core according to any one of claims 1-6, wherein said magnetic material is an amorphous material. 8. The core according to any one of claims 1-7, wherein said leg portions have an essentially circular cross-sectional area. 9. The core according to any one of claims 1-7, wherein said leg portions have an essentially elliptic cross-sectional area. 10. The core according to any one of claims 1-9, wherein said leg portions comprise a magnetic composite material. 11. The core according to any one of claims 1-10, wherein a single wire or strip is used in several loops. 12. The core according to any one of claims 1-11, wherein all of said loops (12', 14', 16') have one common leg portion (6'). 13. The core according to any one of claims 1-12, wherein each of said legs (306, 308, 310) comprises a portion (322a-322c) of non-conductive material. 14.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 (1, 101, 201) according to any one of claims 1-11. 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 (6'), wherein said core (1') is a core according to claim 12. 16. 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 (301) according to claim 13. 17. A method of manufacturing a core of magnetic material, said method comprising the following steps: a) winding a first loop (12; 112; 212) 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 (14; 114; 214) 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 (16; 116; 216) 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. 18. The method according to claim 17, wherein said loops are wound separately, preferably on stands with conical cross-section.