Current sensor assembly

• US 7,557,563 B2
• Filed: 01/19/2006
• Issued: 07/07/2009
• Est. Priority Date: 01/19/2005
• Status: Active Grant

• Current Assignee: Power Measurement Ltd. (Schneider Electric SE)
• Original Assignee: Power Measurement Ltd. (Schneider Electric SE)
• Inventors: Loewen, Daniel N., Harding, Stewart J., Ricci, Marc A., Hancock, Martin A., Gunn, Colin N., Cowan, Peter C.
• Primary Examiner(s): Nguyen; Ha Tran T
• Assistant Examiner(s): ISLA RODAS, RICHARD
• Application Number:
  US11/335,793
• Publication Number:
  US 20060279910A1
• Time in Patent Office: 1,265 Days
• Field of Search: 324/127, 324/117.R, 324/117.H, 324/158.1
• US Class Current: 324/127
• CPC Class Codes: G01R 1/18 Screening arrangements against electric or magnetic fields, e.g. against earth's field
• CPC Class Codes: G01R 1/22 Tong testers acting as secondary windings of current transformers
• CPC Class Codes: G01R 15/183 using transformers with a magnetic core
• CPC Class Codes: G01R 15/186 using current transformers with a core consisting of two or more parts, e.g. clamp-on type G01R15/142 - G01R15/16 take precedence; tong testers G01R1/22

Abstract

A sensor apparatus for measuring power parameters on a power conductor, such as a high voltage transmission line may include a corona structure, an electronics assembly and a conductor mountable device. The corona structure may define an outer boundary surrounding the electronics assembly and the conductor mountable device. The corona structure may shield the electronic assembly and conductor mountable device from a corona produceable with the power conductor. The conductor mountable device may be a power parameter measurement device, such as a current sensor assembly. The current sensor assembly may be a split-core design that includes multiple transformer cores. The electronics assembly and the conductor mountable device may powered from a line voltage suppliable on the power conductor. Data may be wirelessly transmitted and received with the sensor apparatus.

Claims

1. A current sensor assembly comprising:

a housing;

a carrier moveably coupled with said housing and moveable with respect to said housing;

a plurality of current transformer cores, a main winding, and a compensation winding disposed in said housing, wherein said carrier supports said current transformer cores in at least one dimension and substantially maintains alignment of said current transformer cores; and

a compensation circuit included in said housing and coupled with said compensation winding, said compensation circuit configured to actively compensate for a ratio and a phase error of a line current measured with said current sensor assembly, wherein said compensation winding encircles at least one of said current transformer cores without encircling said carrier, and said main winding encircles said compensation winding and said current transformer cores.

2. The current sensor assembly of claim 1, wherein:

said current transformer cores comprise a plurality of discrete core portions.

3. The current sensor assembly of claim 2, wherein:

said carrier comprises a plurality of carriers, and

each of said carriers comprises at least one channel that accommodates at least a portion of at least one of said first or said second core portions.

4. The current sensor assembly of claim 3, further comprising a bonding agent operative to fixedly bond at least one of said discrete core portions with at least one of said carriers.

5. The current sensor assembly of claim 2, wherein said discrete core portions include a first core portion and a second core portion that are aligned to form a main core that surrounds a portion of a conductor and measure an AC current.

6. The current sensor assembly of claim 5, wherein said discrete core portions include a third .core portion and a fourth core portion that are aligned to form a compensation core that compensates measurement by said main core.

7. The current sensor assembly of claim 1, wherein said carrier comprises at least one channel formed to accommodate at least one of said transformer cores.

8. The current sensor assembly of claim 1, wherein said carrier is fixedly coupled with a pin and said housing is formed with a slot, wherein said pin extends from said carrier and is disposed in said slot to moveably coupled said carrier with said housing.

9. The current sensor assembly claim 1, further comprising a bonding agent that fixedly bonds said transformer cores with said carrier.

10. The current sensor assembly of claim 1, wherein said carrier comprises at least one channel, said at least one channel formed to accommodate a combined cross-section of said compensation winding and said one of said current transformer cores.

11. The current sensor assembly of claim 10, further comprising a bonding agent disposed in said first channel in contact with a surface of said compensation winding and said one of said current transformer cores.

12. The current sensor assembly of claim 1, further comprising an electronic assembly included in the current sensor assembly, the electronic assembly comprising a communication circuit and a power supply operable to supply power to said current sensor assembly.

13. A current sensor assembly comprising:

a first housing assembly and a second housing assembly configured to each surround a portion of a conductor; and

a first winding assembly movably disposed in said first housing assembly, and a second winding assembly movably disposed in said second housing assembly;

wherein said first housing assembly and said second housing assembly are transitional between an opening position and a closed position, and

wherein said first winding assembly and said second winding assembly are movable with respect to said first housing assembly and said second housing assembly, respectively, to align said first winding assembly with said second winding assembly, and

wherein at least one of said first housing assembly or said second housing assembly, or combinations thereof, comprises a current sensor electronic device configured to process a measured power parameter, wherein said current sensor electronic device includes compensation circuitry configured to actively compensate for ratio and phase errors.

14. The current sensor assembly of claim 13, wherein said first housing assembly and said second housing assembly are positionable apart in said open position to enable placement of said first housing assembly and said second housing assembly to partially surround a conductor.

15. The current sensor assembly of claim 13, wherein said first winding assembly comprises a first contact surface and said second winding assembly comprises a second contact surface, wherein said first contact surface and said second contact surface are separated when said first housing assembly and said second housing assembly are in said open position, and said first contact surface and said second contact surface are contiguously aligned when said first housing assembly and said second housing assembly are in said closed position.

16. The current sensor assembly of claim 13, wherein each of said first housing assembly and said second housing assembly are formed to define a slot and each of said first winding assembly and said second winding assembly comprise a pin positioned to be disposed in said slot.

17. The current sensor assembly of claim 13, wherein each of said first winding assembly and said second winding assembly comprise a carrier and a plurality of current transformer cores disposed in said carrier.

18. The current sensor assembly of claim 13, wherein said first housing assembly and said second housing assembly comprise inner mating surfaces that mateably align when said first housing assembly and said second housing assembly are positionable together in said closed position, wherein said inner mating surfaces comprise interlocking teeth.

19. The current sensor assembly of claim 18, wherein said interlocking teeth extend away from said inner mating surfaces a determined distance to protect a contact surface included on each of said first winding assembly and said second winding assembly when said first housing assembly and said second housing assembly are in said open position and are positionable to partially surround a conductor.

20. The current sensor assembly of claim 19, further comprising a shield coupled with at least one of the first housing assembly and said second housing assembly, wherein said shield enables said first housing assembly and said second housing assembly to be centered on a conductor.

21. The current sensor assembly of claim 13, wherein said pivot point comprises an interleaved rotating hinge formed to be part of said first housing assembly and said second housing assembly.

22. The current sensor assembly of claim 21, wherein said pivot point comprises an interleaved rotating hinge formed to be part of said first housing assembly and said second housing assembly, or combinations thereof, comprises a power supply circuit.

23. The current sensor assembly of claim 13, wherein at least one of said first housing assembly and said second housing assembly, or the combination thereof, are configured to receive a hotstick and are operative to be manually transitioned between said open position and said closed position with said hotstick.

24. The current sensor assembly of claim 13, wherein at least one of said first housing assembly or said second housing assembly, or combinations thereof, comprises a power supply circuit.

25. The current sensor assembly of claim 24, wherein said power supply circuit comprises a battery.

26. The current sensor assembly of claim 13, wherein said first housing assembly and said second housing assembly each comprise a body and an outer covering, and said body and said outer covering are constructed of electrically conductive material.

27. The current sensor assembly of claim 26, wherein said body and said outer covering provide both an electromagnetic shield and an environmental shield, and wherein said environmental shield is operative as a liquid and dust tight enclosure.

28. The current sensor assembly of claim 13, wherein said first housing assembly and said second housing assembly each comprise a plurality of surfaces that are positionable adjacent a conductor, said surfaces being separated by a non-conductive gap to eliminate a conductive path there between.

29. The current sensor assembly of claim 13, wherein said first winding assembly and said second winding assembly are contiguously aligned when said first housing assembly and said second housing assembly are in said closed position to surround said conductor, and are spaced apart from each other in said open position.

30. The current sensor assembly of claim 13, wherein said first winding assembly and said second winding assembly comprise a plurality of current transformer cores.

31. The current sensor assembly of claim 13, wherein said first housing assembly and said second housing assembly each comprising an inner surface operative to be next adjacent said conductor and, when in said closed position, are positioned in parallel and separated by a gap formed to minimize high frequency noise.

32. The current sensor assembly comprising:

a first housing assembly and a second housing assembly configured to each surround a portion of a conductor;

a first winding assembly movably disposed in said first housing assembly, and a second winding assembly movably disposed in said second housing assembly;

wherein said first housing assembly and said second housing assembly are operative to be transitional between an open position and a closed position, and wherein said first winding assembly and said second winding assembly are movable with respect to said first housing assembly and said second housing assembly, respectively, to align said first winding assembly with said second winding assembly; and

an elastic component disposed between at least one of said first housing assembly and said first winding assembly or between said second housing assembly and said second winding assembly, wherein said elastic component is operative to apply a force to said first winding assembly or said second winding assembly to contiguously align a contact surface included on each of said first winding assembly and said second winding assembly when said first housing assembly and said second housing assembly are in said closed position.

33. A sensor apparatus mountable on a power conductor, the sensor apparatus comprising:

a current sensor assembly operative to sense current in a power conductor;

an electronics assembly included within said current sensor assembly;

wherein said current sensor assembly further comprises a housing with a main winding, a compensation winding, a plurality of transformer cores, and a carrier disposed therein,

wherein said carrier is operative to support said transformer cores in parallel in at least one dimension, and is operative to be moveable with respect to said housing,

wherein said compensation winding encircles at least one of said transformer cores without encircling said carrier, and said main winding encircles said compensation winding and said current transformer cores; and

wherein said electronics assembly comprises a communication circuit and a power supply operative to supply power to said current sensor assembly.

34. The sensor apparatus of claim 33, wherein said power is derivable from at least one battery coupled to said current sensor assembly.

35. The sensor apparatus of claim 33, wherein said electronics assembly is at least partially enclosed in said housing.

36. The sensor apparatus of claim 33, wherein said communication circuit is operative to at least one of transmit data or receive at least one of time data and geographic position data, or combinations thereof.

37. The sensor apparatus of claim 33, wherein said communication circuit is operative to enable communication between said current sensor assembly and a ground based processor that is external to said sensor apparatus.

38. The sensor apparatus of claim 33, wherein said power supply comprises a transformer that includes a primary winding and a secondary winding, wherein said power conductor is electrically coupled with said primary winding, and said secondary winding is operative to supply power to said current sensor assembly and said electronics assembly.