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

• US 20080048655A1
• Filed: 07/13/2007
• Published: 02/28/2008
• Est. Priority Date: 07/14/2006
• Status: Active Grant

• Current Assignee: Epcos AG (TDK Corporation)
• Original Assignee: LISA Drã¤Xlmaier GmbH (Fritz Dräxlmaier Holding GmbH), Epcos AG (TDK Corporation)
• Inventors: Hausperger, Christian, Rollgen, Bernhard, Kindler, Edgar
• Granted Patent: US 7,923,986 B2
• Time in Patent Office: Days
• US Class Current: 324/260
• CPC Class Codes: G01R 15/185 with compensation or feedback windings or interacting coils, e.g. 0-flux sensors using galvano-magnetic field sensors G01R15/20; conversion of DC into AC using transductors G01R19/20
• CPC Class Codes: G01R 15/207 Constructional details independent of the type of device used

Abstract

A device for measuring a current flowing in an electrical conductor. The device comprises a magnetic circuit coupled to an electrical conductor. The magnetic circuit has an air gap and a magnetic field sensitive component disposed in the air gap to measure a magnetic field generated by the electrical conductor. A control core has a control winding configured to control an effective length of the air gap when the control winding is energized. A magnetic shield at least partially encloses the magnetic circuit, the magnetic field sensitive component and the control core.

Claims

1. A device for measuring a current flowing in an electrical conductor, said device comprising:

a magnetic circuit adapted to be coupled to an electrical conductor, the magnetic circuit having an air gap;

a magnetic field sensitive component disposed in the air gap to measure a magnetic field generated by the electrical conductor;

at least one control core having a control winding configured to control an effective length of the air gap when the control winding is energized; and

a magnetic shield that at least partially encloses the magnetic circuit, the magnetic field sensitive component and the at least one control core.

2. The device according to claim 1, wherein the magnetic shield comprises a box-like container that at least partially encloses the magnetic circuit, the magnetic field sensitive component and the at least one control core.

3. The device according to claim 2, wherein the container is open on at least a side.

4. The device according to claim 2, wherein the container is substantially closed except for through-holes for electrical and/or magnetic conductors.

5. The device according to claim 1, wherein the magnetic shield comprises an outermost spatial boundary of the device.

6. The device according to claim 1, wherein the magnetic shield includes a metallic material.

7. The device according to claim 1, wherein the magnetic shield is disposed to provide a substantial shield against an external magnetic field.

8. The device according to claim 1, wherein the magnetic shield has at least one through hole to provide access for conductors.

9. The device according to claim 1, wherein the at least one control core comprises two control cores disposed in the air gap.

10. The device according to claim 9, wherein the magnetic field sensitive component is disposed between the control cores.

11. The device according to claim 1, wherein the device is disposed in the vicinity of a conductor of a vehicle battery.

12. The device according to claim 1, wherein the device is disposed in the vicinity of an electrical consumer load of a vehicle.

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

providing a device that comprises;

a magnetic circuit adapted to be coupled to an electrical conductor, the magnetic circuit having an air gap;

a magnetic field sensitive component disposed in the air gap to measure a magnetic field generated by the electrical conductor;

at least one control core having a control winding configured to control an effective length of the air gap when the control winding is energized; and

a magnetic shield that at least partially encloses the magnetic circuit, the magnetic field sensitive component and the at least one control core; and

measuring current flowing through the electrical conductor without exciting the control winding of the at least one control core; and

measuring current flowing through the electrical conductor while exciting the control winding to saturate the at least one control core.

14. The method according to claim 13, wherein the at least one control core comprises two control cores, the method further comprising:

measuring current flowing through the electrical conductor while exciting one of the two two control cores

15. The method of claim 13, performed in a motor vehicle to monitor currents in an on-board electrical system of the motor vehicle.