Common mode, differential mode three phase inductor

• US 7,768,373 B2
• Filed: 12/17/2008
• Issued: 08/03/2010
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: MTE Corporation (Steel Partners Holdings LP)
• Original Assignee: Cramer Coil & Transformer Co., Inc.
• Inventors: Shudarek, Todd Alexander
• Primary Examiner(s): Enad; Elvin G
• Assistant Examiner(s): HINSON, RONALD
• Application Number:
  US12/337,454
• Publication Number:
  US 20090261939A1
• Time in Patent Office: 594 Days
• Field of Search: 336/214, 336/215, 336/212
• US Class Current: 336/212
• 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 37/00 Fixed inductances not covered by group H01F17/00
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

An inductor includes common mode and differential mode flux paths. The inductor comprises a first core having a first segment, a second segment extending from the first segment and a first bridge segment extending from the second segment; a first wiring arrangement at least partially disposed around the first segment; a second core having a third segment, a fourth segment extending from the third segment and a second bridge segment extending from the fourth segment; and a second wiring arrangement at least partially disposed around the third segment; wherein the first segment, second segment, third segment and fourth segment cooperate to promote the common mode flux path, and the first bridge segment and the second bridge segment cooperate to promote the differential mode flux path.

Claims

1. An inductor including common mode and differential mode flux paths, the inductor comprising:

a first core having a first segment, a second segment extending from the first segment and a first bridge segment extending from the second segment;

a first wiring arrangement at least partially disposed around the first segment;

a second core having a third segment, a fourth segment extending from the third segment and a second bridge segment extending from the fourth segment;

a second wiring arrangement at least partially disposed around the third segment;

a third core having a fifth segment, a sixth segment extending from the fifth segment and a third bridge segment extending from the sixth segment;

a third wiring arrangement at least partially disposed around the fifth segment; and

wherein the first segment, second segment, third segment, fourth segment, fifth segment and sixth segment cooperate to promote the common mode flux path, and the first bridge segment, the second bridge segment and the third bridge segment extend substantially toward a central axis of the inductor and cooperate to promote the differential mode flux path.

2. The inductor of claim 1, wherein the second segment extends from a longitudinal end of the first segment.

3. The inductor of claim 1, wherein the first segment and the second segment define a 120 degree angle therebetween.

4. The inductor of claim 1, wherein the first bridge segment extends substantially perpendicular from the second segment.

5. The inductor of claim 1, wherein the first core is a single piece of metal material and wherein an arcuate wall at least partially defines the second segment and the first bridge segment.

6. The inductor of claim 1, wherein the first core includes a plurality of laminations stacked together.

7. The inductor of claim 6, wherein each of the laminations include an aperture in relation with the first bridge segment, the apertures of the laminations forming a core aperture for receiving a fastener.

8. The inductor of claim 1, wherein the first wiring arrangement includes a first coil and a second coil disposed around the first segment, the first coil being electrically connected to the second coil for affecting the common mode flux path.

9. The inductor of claim 1, wherein a longitudinal end of the first bridge segment opposite the second segment is adjacent a longitudinal end of the second bridge segment opposite the fourth segment, the separation between the longitudinal end of the first bridge segment and the longitudinal end of the second bridge segment affecting the differential mode flux path.

10. The inductor of claim 1, wherein a longitudinal end of the first segment opposite the second segment is adjacent a longitudinal end of the fourth segment opposite the third segment such that the longitudinal end of the first segment and the longitudinal end of the fourth segment form a gap therebetween for affecting the common mode flux path.

11. The inductor of claim 10, wherein a spacer including a nonmagnetic material is placed within the gap for affecting the common mode flux path.

12. The inductor of claim 1, further comprising a band extending the periphery of the first core and the second core for coupling the first core and the second core to one another, and a supporting bracket receiving the band for securing the first core and the second core to the bracket.

13. A method of manufacturing an inductor having common mode and differential flux paths, the method comprising:

providing a first core having a first segment, a second segment extending from the first segment and a first bridge segment extending from the second segment;

disposing a first wiring arrangement at least partially around the first segment;

providing a second core having a third segment, a fourth segment extending from the third segment and a second bridge segment extending from the fourth segment;

disposing a second wiring arrangement at least partially around the third segment;

providing a third core having a fifth segment, a sixth segment extending from the fifth segment and a third bridge segment extending from the sixth segment;

disposing a third wiring arrangement at least partially around the fifth segment; and

arranging the first core, the second core, and the third core such that the first segment, second segment, third segment, fourth segment, fifth segment, and sixth segment define a central portion of the inductor and cooperate to promote the common mode flux path and the first bridge segment, the second bridge segment and the third bridge segment extend into the central portion of the inductor and cooperate to promote the differential mode flux path.

14. The method of claim 13, wherein placing the first core adjacent the second core includes placing a longitudinal end of the first segment opposite the second segment adjacent a longitudinal end of the fourth segment opposite the third segment.

15. The method of claim 14, further comprising adjusting the distance between the longitudinal end of the first segment and the longitudinal end of the fourth segment to affect the common mode flux path.

16. The method of claim 14, further comprising selectively forming a gap between the longitudinal end of the first segment and the longitudinal end of the fourth segment to affect the common mode flux path.

17. The method of claim 16, further comprising placing a spacer including a nonmagnetic material within the gap for affecting the common mode flux path.

18. The method of claim 13, wherein placing the first core adjacent the second core includes placing a longitudinal end of the first bridge segment opposite the second segment adjacent a longitudinal end of the second bridge segment opposite the fourth segment.

19. The method of claim 18, further comprising adjusting the distance between the longitudinal end of the first bridge segment and the longitudinal end of the second bridge segment for affecting the differential mode flux path.

20. The method of claim 18, further comprising adjusting the width of at least one of the first bridge segment and the second bridge segment for affecting the differential mode flux path.

21. The method of claim 13, wherein the first wiring arrangement includes a first coil and a second coil, wherein the disposing the first wiring arrangement includes mounting the first coil and the second coil on the first segment, and wherein the method further comprises electrically coupling the first coil with the second coil.

22. The method of claim 21, wherein the mounting the first coil and the second coil includes placing the first coil in the same orientation as the second coil.

23. The method of claim 21, wherein the mounting the first coil and the second coil includes placing the first coil in the opposite orientation as the second coil.

24. The method of claim 13, further comprising

providing a band and a supporting bracket,

placing the band along the periphery of the first core and the second core, and

coupling the first core and the second core to the bracket with the band.

25. An apparatus for eliminating overvoltages due to resonances, the apparatus comprising:

a three-phase inductor having common mode and differential mode flux paths, the inductor further including a first core, a second core, and a third core, each core having a first segment, a second segment extending from the first segment, respectively, and a bridge segment extending from the second segment, respectively, and a first wiring arrangement, a second wiring arrangement and a third wiring arrangement disposed around each respective first segment; and

a first circuit in parallel arrangement with the first wiring arrangement, a second circuit in parallel arrangement with the second wiring arrangement, and a third circuit in parallel with the third wiring arrangement, each of the first circuit, the second circuit, and the third circuit including a respective capacitive element and a respective resistive element in series arrangement,

wherein the bridge segments extend substantially toward a central axis of the three-phase inductor.

26. A motor assembly comprising a drive, a motor, and the apparatus of claim 25 connected in circuit between the drive and the motor.