Sensor devices and methods for use in sensing current through a conductor

• US 8,912,807 B2
• Filed: 09/09/2011
• Issued: 12/16/2014
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: Aclara Meters LLC (Hubbell, Inc.)
• Original Assignee: General Electric Company
• Inventors: Bietz, Steven Lee, Chamarti, Subramanvam Satyasurya
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): MILLER, DANIEL R
• Application Number:
  US13/228,924
• Publication Number:
  US 20130063161A1
• Time in Patent Office: 1,194 Days
• Field of Search: None
• US Class Current: 324/654
• CPC Class Codes: G01R 15/181 using coils without a magnetic core, e.g. Rogowski coils

Abstract

Sensor devices and related methods disclosed. One example sensor device includes a Rogowski coil defining an aperture and a dielectric material at least partially enclosing the Rogowski coil. The dielectric material has a dielectric constant of at least about 3.5. The dielectric material is configured such that, when a conductor is at least partially inserted within the aperture, at least a portion of the dielectric material is positioned between the Rogowski coil and the conductor.

Claims

1. A sensor device for use in detecting current in a conductor, said sensor device comprising:

a Rogowski coil defining an aperture; and

a dielectric material at least partially enclosing said Rogowski coil, said dielectric material comprising a first part and a second part and having a dielectric constant of at least about 3.5 at about 10 to 1000 Hertz (Hz), said dielectric material configured such that, when a conductor is at least partially inserted within said aperture, at least said first part of said dielectric material is positioned between said Rogowski coil and the conductor, wherein said first part of said dielectric material has a first thickness, said second part of said dielectric material has a second thickness that is less than the first thickness, and said second part of said dielectric material is positioned adjacent to said Rogowski coil and is opposite said aperture, wherein the first thickness is measured radially and normal to the conductor.

2. The sensor device of claim 1, further comprising an enclosure at least partially enclosing said Rogowski coil, said enclosure comprising at least a portion of said dielectric material.

3. The sensor device of claim 2, wherein said dielectric material has a dielectric constant of at least about 5.0 at about 10 to 1000 Hz.

4. The sensor device of claim 3, wherein said dielectric material has a dielectric constant of at least about 8.0 at about 10 to 1000 Hz.

5. The sensor device of claim 4, wherein said dielectric material has a dielectric constant of at least about 10.0 at about 10 to 1000 Hz.

6. The sensor device of claim 2, wherein said dielectric material comprises a polybutylene terephthalate (PBT) thermoplastic material.

7. The sensor device of claim 2, wherein said enclosure comprises a first portion and a second portion releasably coupled to said first portion to substantially enclose said Rogowski coil.

8. The sensor device of claim 2, wherein at least one said first part and said second part of said dielectric material has a thickness of between about 1.0 millimeters and about 8.0 millimeters.

9. The sensor device of claim 1, further comprising a non-magnetic substrate structured to support said Rogowski coil, said substrate comprising a plurality of bobbins, said plurality of bobbins comprising a second dielectric material.

10. A utility meter for use in transmitting electrical energy from a power source to a user;

said utility meter comprising;

a conductor; and

a sensor device at least partially circumscribing said conductor, said sensor device including a Rogowski coil defining an aperture and a dielectric material at least partially enclosing said Rogowski coil, said dielectric material comprising a first part and a second part and having a dielectric constant of greater than about 3.5 at about 10 to 1000 Hertz (Hz), at least said first part of said dielectric material positioned between said Rogowski coil and said conductor, wherein said first part of said dielectric material has a first thickness, said second part of said dielectric material has a second thickness that is less than the first thickness, and said second part of said dielectric material is positioned adjacent to said Rogowski coil and is opposite said aperture, wherein the first thickness is measured radially and normal to said conductor.

11. The utility meter of claim 10, wherein said sensor device comprises a mount forming a friction fit with said conductor.

12. The utility meter of claim 11, further comprising an enclosure substantially enclosing said Rogowski coil, and wherein said enclosure comprises said mount and said dielectric material.

13. The utility meter of claim 12, wherein said enclosure includes a first portion and a second portion releasably engaged to said first portion to substantially enclose said Rogowski coil.

14. The utility meter of claim 13, wherein said first portion of the enclosure defines a third thickness between about 1.0 millimeters and about 5.0 millimeters and said second portion of the enclosure defines a fourth thickness between about 1.0 millimeters and about 5.0 millimeters, and wherein the third thickness is different than the fourth thickness.

15. The utility meter of claim 12, wherein said enclosure comprises a substantially toroidal-shaped enclosure.

16. The utility meter of claim 10, further comprising a second conductor, wherein at least a portion of said dielectric material is disposed between the second conductor and the Rogowski coil.

17. The utility meter of claim 10, wherein said dielectric material has a dielectric constant of at least about 6.0 at about 10 to 1000 Hz.

18. A method of fabricating a sensor device for sensing current through a conductor, the method comprising:

providing a Rogowski coil defining an aperture; and

at least partially enclosing the Rogowski coil within a dielectric material comprising a first part and a second part such that, when the coil is positioned about a conductor, the first part of the dielectric material is positioned between the Rogowski coil and the conductor, the dielectric material having a dielectric constant of greater than or equal to about 3.5 at about 10 to 1000 Hertz (Hz), wherein the first part of the dielectric material has a first thickness, the second part of the dielectric material has second thickness that is less than the first thickness, and the second part of the dielectric material is positioned adjacent to the Rogowski coil and is opposite the aperture, wherein the first thickness is measured radially and normal to the conductor.

19. The method of claim 18, wherein at least partially enclosing the Rogowski coil comprises assembling a first portion of an enclosure and a second portion of the enclosure with the Rogowski coil disposed therebetween, and wherein the enclosure comprises the dielectric material.

20. The method of claim 19, wherein at least partially enclosing the Rogowski coil includes substantially enclosing the Rogowski coil within the enclosure, the enclosure including a mount structured to form a friction fit with a conductor received therethrough.