Electromagnetic Induction Device

Patent metadata

Field	Value
Publication number	US-2016372248-A1
Application number	US-201615169145-A
Country	US
Kind code	A1
Filing date	May 31, 2016
Priority date	Jun 17, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

An electromagnetic induction device including a magnetic core having a limb which has a first end and a second end, windings arranged around the limb, and a housing including magnetic material, which housing defines a space in which the magnetic core and the windings are arranged, wherein the housing defines a return path for the primary magnetic flux, enabling primary magnetic flux from the first end of the limb to flow via the housing to the second end of the limb.

First claim

1 . An electromagnetic induction device that is a transformer or a reactor, comprising:
a magnetic core having a limb which has a first end and a second end, windings arranged around the limb, and a tank comprising magnetic material, which tank defines a space in which the magnetic core and the windings are arranged, wherein the tank defines a return path for the primary magnetic flux which is magnetic flux in the magnetic core, enabling primary magnetic flux from the first end of the limb to flow via the housing to the second end of the limb.

2 . The electromagnetic induction device as claimed in claim 1 , comprising a flux density reducer arranged between the first end of the limb and the tank, which flux density reducer has a cross sectional dimension greater than a largest cross sectional dimension of the limb.

3 . The electromagnetic induction device as claimed in claim 2 , wherein the cross sectional dimension of the flux density reducer is at least the square root of two times the largest cross sectional dimension of the limb.

4 . The electromagnetic induction device as claimed in claim 2 , wherein the flux density reducer is a polymer magnet or comprises iron dust, or a composite made of compressible iron powder which has a compaction pressure threshold in the range 60-200 ksi and powder having a permeability above 1000.

5 . The electromagnetic induction device as claimed in claim 1 , wherein the limb has a cross section which increases towards the first end such that it is at least the square root of two times a cross sectional dimension of the limb at the midpoint midpoint of the limb in the axial direction.

6 . The electromagnetic induction device as claimed in claim 1 , wherein the magnetic core comprises a plurality of limbs, and wherein the tank defines an upper yoke and a lower yoke which enables the primary magnetic flux to circulate between the limbs.

7 . The electromagnetic induction device as claimed in claim 1 , wherein the tank has a top part and a bottom part which are made of silicon steel comprising silicon in the range 3-6% by mass.

8 . The electromagnetic induction device as claimed in claim 1 , wherein the housing has a side wall which comprises amorphous material.

9 . The electromagnetic induction device as claimed in claim 1 , wherein the tank is made of carbon steel.

10 . The electromagnetic induction device as claimed in claim 1 , wherein the housing has a top part and a bottom part, wherein the top part and the bottom part have a grain-oriented structure, wherein grain orientation of the top part and the bottom part is along magnetic flux lines of the return path.

11 . The electromagnetic induction device as claimed in claim 1 , wherein the housing has circular cross section along essentially its entire extension in the axial direction of the limb.

12 . The electromagnetic induction device as claimed in claim 1 , wherein the tank has elliptical cross section along essentially its entire extension in the axial direction of the limb.

13 . The electromagnetic induction device as claimed in claim 1 , wherein the tank has a side wall provided with a cut extending from a top part of the tank to a bottom part of the tank.

14 . The electromagnetic induction device as claimed in claim 13 , wherein the side wall comprises a plurality of concentrically arranged sheet, wherein each sheet is provided with the cut.

15 . The electromagnetic induction device as claimed in claim 14 , wherein each sheet comprises one grain-oriented steel, non-grain oriented steel, and amorphous steel.

16 . The electromagnetic induction device as claimed in claim 3 , wherein the flux density reducer is a polymer magnet or comprises iron dust, or a composite made of compressible iron powder which has a compaction pressure threshold in the range 60-200 ksi and powder having a permeability above 1000.

Assignees

• Abb Technology Ltd

Inventors

• Pradhan Manoj
• Russberg Gunnar

Classifications

• H01F2003/103

  Magnetic circuits with permanent magnets · CPC title

• H01F27/346

  Preventing or reducing leakage fields (using magnetic shields H01F27/36; using auxiliary windings H01F27/38) · CPC title

• H01F27/24 Primary

  Magnetic cores · CPC title

• H01F3/10

  Composite arrangements of magnetic circuits · CPC title

• H01F27/022

  Encapsulation · CPC title