Arrangement and method for measuring a current flowing in an electrical conductor

• US 8,294,452 B2
• Filed: 02/03/2010
• Issued: 10/23/2012
• Est. Priority Date: 08/03/2007
• Status: Expired due to Fees

• Current Assignee: Epcos AG (TDK Corporation)
• Original Assignee: Epcos AG (TDK Corporation)
• Inventors: Roellgen, Bernhard, Neudecker, Martin
• Primary Examiner(s): Hollington, Jermele M
• Application Number:
  US12/699,333
• Publication Number:
  US 20100188072A1
• Time in Patent Office: 993 Days
• Field of Search: None
• US Class Current: 324/117.H
• CPC Class Codes: G01R 15/207 Constructional details independent of the type of device used

Abstract

An arrangement for measuring a current flowing in an electrical conductor includes a magnetic circuit, for coupling to the electrical conductor, the magnetic circuit has an air gap. A magnetic field-sensitive component that serves for measuring the magnetic field generated by the electrical conductor is situated between the arms of the magnetic circuit. Two control cores are arranged in the air gap of the magnetic circuit. The control cores each include a control winding for magnetically saturating the respective control core and are arranged on both sides of the electrical conductor.

Claims

1. An arrangement for measuring a current flowing in an electrical conductor, the arrangement comprising:

a magnetic circuit having an air gap for coupling to the electrical conductor;

a magnetic field-sensitive component arranged in the magnetic circuit and configured to measure a magnetic field generated by the electrical conductor; and

first and second control cores arranged in parallel in the air gap, so that the electrical conductor can be situated between the control cores, wherein the control cores each comprise a control winding for magnetically saturating the respective control core, wherein the second control core is arranged parallel to the magnetic field-sensitive component;

wherein the first and second control cores are independently controllable and are arranged so that the arrangement is configured to;

measure flux density permeating the magnetic field-sensitive component when the control cores are unsaturated; and

measure flux density permeating the magnetic field-sensitive component when the first core is saturated and the second core is unsaturated; and

measure flux density permeating the magnetic field-sensitive component when the second control core is saturated and the first control core is unsaturated; and

measure flux density permeating the magnetic fields sensitive component when both the first and second control cores are saturated.

2. The arrangement according to claim 1, wherein the first control core is arranged on a first side of the electrical conductor and the second control core is arranged on a second side of the electrical conductor.

3. The arrangement according to claim 1, wherein the magnetic circuit comprises an additional winding.

4. The arrangement according to claim 1, wherein the first and second control cores lie in a common plane.

5. The arrangement according to claim 1, wherein the magnetic circuit extends around the electrical conductor.

6. The arrangement according to claim 1, wherein the first and second control cores each comprise a ferrite core.

7. The arrangement according to claim 1, wherein the first and second control cores each comprise a rectangular frame and each comprise a control winding for saturating the control cores on at least one side of the frame.

8. The arrangement according to claim 1, wherein the first and second control cores each comprise a control winding on two opposite sides.

9. The arrangement according to claim 1, wherein the first and second control cores have saturation even in a case of very large currents.

10. The arrangement according to claim 1, wherein the magnetic field-sensitive component is a Hall sensor.

14. The arrangement according to claim 1, further comprising the electrical conductor located between the control cores.

11. A method for measuring a current flowing in an electrical conductor, the method comprising:

locating the electrical conductor within an air gap of a magnetic circuit, first and second control cores being arranged in parallel in the air gap, wherein the control cores each comprise a control winding for magnetically saturating the respective control core;

measuring a flux density permeating a magnetic field-sensitive component arranged in the magnetic circuit in parallel with at least the first control core, the flux density being measured in a case of unsaturated control cores;

measuring the flux density permeating the magnetic field-sensitive component in a case of saturation of the first control core;

measuring the flux density permeating the magnetic field-sensitive component in a case of saturation of the second control core; and

measuring the flux density permeating the magnetic field-sensitive component in the case of saturation of the first and second control cores.

12. The method according to claim 11, further comprising calculating the current flowing through the electrical conductor from the measured flux densities.

13. The method according to claim 12, further comprising calculating a sensitivity of the magnetic field-sensitive component from the measured flux densities.

15. A circuit comprising:

a magnetic circuit having an air gap;

an electrical conductor located in the air gap;

a first control core arranged in the air gap, wherein the first control core comprises a first control winding for magnetically saturating the first control core;

a second control core arranged in the air gap in parallel with the first control core, wherein the second control core comprises a second control winding for magnetically saturating the second control core; and

a magnetic field-sensitive component arranged in the magnetic circuit and configured to measure a magnetic field generated by the electrical conductor that is arranged in the air gap and surrounded by the magnetic circuit on a top side and on a bottom side of the electrical conductor, by the first control core on a left side of the electrical conductor and by the second control core on a right side of the electrical conductor, the top side opposite the bottom side and the left side opposite the right side;

wherein the first and second control cores are independently controllable and are arranged so that the arrangement is configured to;

measure flux density permeating the magnetic field-sensitive component when the first and second control cores are unsaturated; and

measure flux density permeating the magnetic field-sensitive component when the first core is saturated and the second core is unsaturated; and

measure flux density permeating the magnetic field-sensitive component when the second control core is saturated and the first control core is unsaturated; and

measure flux density permeating the magnetic fields sensitive component when first and second control cores are saturated.

16. The circuit according to claim 15, wherein the magnetic field-sensitive component is arranged parallel to the first control core and to the second control core.

17. A magnetic apparatus comprising:

a U-shaped magnetic circuit that includes a first extending portion, a second extending portion parallel to the first extending portion and a base portion between a first end the first extending portion and a second end of the second extending portion, wherein an air gap is enclosed on three sides by the first and second extending portions and the base portion;

a magnetic field-sensitive component arranged in series with the magnetic circuit and configured to measure a magnetic field within the air gap;

a first control core arranged in the air gap adjacent second ends of the first and second extending portions, wherein the first control core comprises a first control winding for magnetically saturating the first control core; and

a second control core arranged in the air gap adjacent the base portion and parallel to the magnetic field-sensitive component, the second control core in parallel with but spaced from the first control core, wherein the second control core comprises a second control winding for magnetically saturating the second control core.