Electrical parameter sensing module for mounting on and removal from an energized high voltage power conductor

• US 4,794,327 A
• Filed: 05/11/1987
• Issued: 12/27/1988
• Est. Priority Date: 04/13/1983
• Status: Expired due to Term

• Current Assignee: Undersground Systems, Inc.
• Original Assignee: Roosevelt A. Fernandes
• Inventors: Fernandes, Roosevelt A.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Nguyen, Vinh P.
• Application Number:
  US07/048,646
• Time in Patent Office: 596 Days
• Field of Search: 324/126, 324/127, 324/142, 340/657, 340/870.17, 340/870.16, 364/483, 364/492, 320/56
• US Class Current: 324/126
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 1/143 for measuring surface temperatures
• CPC Class Codes: G01R 15/142 Arrangements for simultaneous measurements of several parameters employing techniques covered by groups G01R15/14 - G01R15/26
• CPC Class Codes: G01R 15/26 using modulation of waves other than light, e.g. radio or acoustic waves
• CPC Class Codes: G01R 23/16 Spectrum analysis; Fourier analysis
• CPC Class Codes: H01J 13/00 Discharge tubes with liquid-pool cathodes, e.g. metal-vapour rectifying tubes
• CPC Class Codes: H02J 13/00022 using wireless data transmission
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/00 Systems supporting electrical power generation, transmission or distribution
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 40/126 using wireless data transmission

Abstract

A toroidal sensor module having a metallic outer skin and mounting means for installation upon and removal from an energized power conductor providing synchronized measurements of electrical parameters. In one embodiment the module is adapted to measure the values of voltage, current and phase angle of the conductor upon which it is mounted, and to communicate data representing such values to a ground station in the vicinity of the sensor module. The voltage and current are sensed simultaneously to provide time-synchronized readings with respect to voltage zero crossings from which the phase relationship is determined. The metallic skin of the module may be either capacitively or electrically coupled to the conductor for purposes of making conductor voltage measurements. The toroidal housing is divided into two, mutually insulated sections to prevent an electrical short circuit loop on any peripheral path on the housing extending through both sections, thereby allowing the electromagnetic field of the conductor to be coupled to sensing elements within the housing.

Claims

1. A sensor module for measuring a plurality of parameters associated with operation of an electric power conductor, said module comprising:

(a) housing means having a metallic outer skin, and containing at least one electrical element responsive to the electromagnetic field associated with said conductor mounted within said housing means, said metallic skin being divided by an insulating member along at least one, complete, peripheral path to prevent an electrical short circuit loop extending entirely around said element, thereby allowing said electromagnetic field to be coupled to said element;

(b) means for mounting said housing upon an energized power conductor;

(c) means carried by said housing for sensing the value of current flow through said conductor;

(d) means including said metallic skin of said housing for sensing the value of the voltage on said conductor;

(e) means carried by said housing for determining the phase relationship between said sensed values of current and voltage; and

(f) means for communicating data representing the respective values of current, voltage and phase angle to a location remote from said sensor module.

2. The sensor module according to claim 1 wherein said current and voltage values are sensed simultaneously to provide time-synchronized readings of current and voltage and said phase relationship is determined from said time-synchronized readings.

3. The invention according to claim 2 wherein said power conductor is an overhead line and said location is at or near ground level in the vicinity of said sensor module.

4. The invention according to claim 3 wherein said data communicating means comprises an RF transmitter and antenna carried by said housing and adapted to transmit said data for reception by an RF receiver at said location.

5. The sensor module according to claim 1 wherein said housing means, including said outer skin, is generally toroidal in shape, is positioned by said mounting means with said conductor extending along the central axis thereof, and is divided into front and rear sections by a plane transverse to said axis, said front and rear sections being electrically insulated from one another at one junction so as not to form any short-circuit loops at any point on the torus at signal frequencies to be measured.

6. The sensor moudle according to claim 5 wherein said housing means is divided into at least two relatively movable sections for mounting upon said conductor.

7. The sensor module according to claim 6 wherein said mounting means includes a central support portion having a conductive member in engagement with said power conductor.

8. The sensor module according to claim 7 wherein the electrical path between said conductive member and said housing is broken by an insulating barrier in said central support.

9. The sensor module according to claim 8 wherein said inner insulating barrier comprises a relatively thin layer of material which functions as a capacitor in aaid voltage sensing means.

10. The sensor module according to claim 9 wherein said capacitor has a high impedance at the highest frequency component to be measured.

11. The sensor module according to claim 10 wherein said voltage sensing means further includes an integrating network having an operational amplifier with first and second inputs respectively connected to said conductor and to said metallic outer skin.

12. The sensor module according to claim 1 wherein said housing is electrically connected to said conductor.

13. The sensor module according to claim 12 wherein said voltage sensing means further include at least one arcuate, conducting disc mounted upon said housing and insulated from said metallic skin thereof, thereby providing one segment of a capacitance voltage divider to ground.

14. The sensor module according to claim 13 wherein said voltage sensing means further includes a high impedance amplifier with first and second inputs respectively connected to said disc and to said metallic outer skin.

15. The sensor module according to claim 1 wherein said means for determining phase angle include means for detecting zero-crossings of current and voltage, and said data transmitting means is adapted to transmit a message of predetermined duration in synchronization with said voltage zero crossings.

16. The sensor module according to claim 1 and further including means carried by sai sensor module for deriving electrical power from the electromagnetic field associated with current flow through said power conductor for powering said communicating means.

17. The sensor module according to claim 16 and further including energy storage means carried by said sensor module for powering said data communicating means when current flow through said power conductor is below a predetermined threshold value.

18. The sensor module according to claim 17 and further including means for charging said energy storage means from the electrostatic field associated with said conductor and said metallic outer skin.

19. The sensor module according to claim 18 and further including means carried by said sensor module for generating an indicating signal when current flow through said conductor is below said threshold value and said conductor is energized.

20. The sensor module according to claim 19 wherein said data transmitting means includes an RF transmitter and means for varying the frequency of data transmissions to conserve energy from said energy storage means.

21. A sensor module for mounting on and removal from an energized, high voltage power conductor for measuring the instantaneous value of voltage on said conductor, said module comprising:

(a) housing means having a metallic outer skin, and containing at least one electrical element responsive to the electromagnetic field associated with said energized conductor mounted within said housing means, said metallic skin being divided by an insulating member along at least one, complete, peripheral path to prevent an electrical short circuit loop extending entirely around said element, thereby allowing said electromagnetic field to be coupled to said element;

(b) mounting means by which said housing means is mounted in surrounding relation to said conductor, said mounting means including an electrically conducting member in engagement with said power conductor;

(c) a relatively thin insulating barrier between said conducting member and said housing which functions as a high impedance capacitor at frequencies at or below the highest frequency to be measured; and

(d) an integrating network having a low impedance operational amplifier with first and second inputs respectively connected to said conductor and to said metallic outer skin, thereby measuring the charging current on said outer skin and hence the voltage on said conductor.

22. A sensor module for mounting on and removal from an energized, high voltage power conductor for measuring the instantaneous value of voltage on said conductor, said module comprising:

(a) housing means having a generally toroidal, metallic outer skin, and containing at least one electrical element responsive to the electromagnetic field associated with said energized conductor mounted within said housing means, said metallic skin being divided by an insulating member along at least one, complete, peripheral path to prevent an electrical short circuit loop extending entirely around said element, thereby allowing said electromagnetic field to be coupled to said element;

(b) mounting means by which said housing means is mounted in surrounding relation to said conductor;

(c) means electrically connecting said metallic skin to said conductor, whereby said metallic skin is at the electrical potential of said conductor;

(d) at least one conducting plate having a length at least several times its width affixed to an inner portion of said toroidal metallic skin with a relatively thin layer of insulating material therebetween to provide one segment of a capacitance voltage divider to earth;

(e) a high impedance amplifier with first and second inputs respectively connected to said plate and to said metallic skin; and

(f) means for measuring the voltage across the output of said amplifier proportional to the line-to-ground potential of said conductor.

23. A sensor module for measuring at least one parameter associated with operation of an electric power conductor, said module comprising:

(a) housing means having a metallic outer skin defining an enclosed space;

(b) means for mounting said housing upon said conductor;

(c) at least one electrical element responsive to the electromagnetic field of said conductor contained within said enclosed space;

(d) said housing means being divided into complementary first and second sections;

(e) means electrically insulating said first and second sections from one another along the periphery to prevent an electrical short circuit loop on any peripheral path on said housing extending through both said first and second sections, thereby allowing said electromagnetic field to be coupled to said element; and

(f) means carried by said housing for measuring at least one parameter associated with operation of said conductor.

24. The sensor module according to claim 23 wherein said housing is generally toroidal in shape and is divided by a plane normal to the toroidal axis so that the segments when brought togethrr surround the conductor in the installed position.

25. The sensor module according to claim 24 wherein said electrical element is a Rogowski coil.

26. The sensor module according to claim 24 wherein said electrical element is a power core excited by said conductor with secondary power pick-off coils.

27. The sensor module according to claim 26 wherein said toroidal housing is further divided by at least one plane parallel to said toroidal axis into relatively movable portions for mounting on said conductor with the latter extending through the toroid.

28. The sensor module according to claim 27 wherein said power core extends around the anterior of said toroidal housing to surround said conductor and is divided with said housing into relatively movable portions including a pair of opposed pole faces, and further including means defining a moisture-proof recess around one of said pole faces and a shroud surrounding and extending outwardly from the other of said pole faces for mating engagement with said recess when said module is mounted on said conductor.

29. The sensor module according to claim 23 and further including a temperature probe mounted upon said module outside said housing means for measuring ambient temperature, and a thermal-reflective, perforated shroud in covering relation to said probe.

30. The sensor module according to claim 29 and further including means essentially thermally insulating said probe from said housing means.

31. The sensor module according to claim 23 and further including a temperature probe mounted upon said module outside said housing means for measuring the temperature of said conductor and means essentially thermally insulating said probe from said housing means.

32. A sensor module for measuring at least one parameter associated with operation of an electric power conductor, said module comprising:

(a) housing means having a metallic outer skin;

(b) means for mounting said housing upon and removing it from an energized power conductor;

(c) at least one electrical element responsive to the electromagnetic field associated with said energized conductor mounted with said housing means, said metallic skin being divided by an insulating member along at least one, complete, peripheral path to prevent an electrical short circuit loop extending entirely around said element, thereby allowing said electromagnetic field to be coupled to said element;

(d) means carried by said housing for measuring at least one parameter associated with operation of said conductor; and

(e) means for communicating data representing the value of said parameter to a location remote from said sensor module.

33. A sensor module for measuring a plurality of parameters associated with operation of an electric power conductor, said module comprising:

(a) housing means having a metallic outer skin, and containing at least one electrical element responsive to the electromagentic field asociated with said energized conductor mounted within said housing means, said metallic skin being divided by an insulating member along at least one, complete, peripheral path to prevent an electrical short circuit loop extending entirely around said element, thereby allowing said electromagentic field to be coupled to said element;

(b) means for mounting said housing upon an energized power conductor;

(c) means carried by said housing for sensing the value of current flow through said conductor;

(d) means including said metallic skin of said housing for sensing the value of the voltage on said conductor; and

(e) means for communicating data representing the respective values of current and voltage to a location remote from said sensor module.

34. A sensor module for measuring a plurality of parameters associated with operation of an electric power conductor, said module comprising:

(a) housing means having a metallic outer skin, and containing at least one electrical element responsive to the electromagnetic field associated with said energized conductor mounted within said housing means, said metallic skin being divided by an insulating member along at least one, complete, peripheral path to prevent an electrical short circuit loop extending entirely around said element, thereby allowing said electromagnetic field to be coupled to said element;

(b) mounting means by which said housing means is mounted in surrounding relation to said conductor, said mounting means including an electrically conducting member in engagement with said power conductor;

(c) means carried by said housing for sensing the value of current flow through said conductor;

(d) a relatively thin insulating barrier between said conducting member and said housing which functions as a high impedance capacitor at frequencies at or below the highest frequency to be measured;

(e) an integrating network having a low impedance operational amplifier with first and second inputs respectively connected to said conductor and to said metallic outer skin, thereby measuring the charging current on said outer skin and hence the voltage on said conductor; and

(f) means for communicating data representing the respective values of current and voltage to a location remote from said sensor module.