Portable self powered line mounted device and method for measuring the voltage of electric power line conductors

• US 9,140,764 B2
• Filed: 11/20/2013
• Issued: 09/22/2015
• Est. Priority Date: 12/21/2012
• Status: Active Grant

• Current Assignee: Murray W. Davis
• Original Assignee: Murray W. Davis
• Inventors: Davis, Murray W.
• Primary Examiner(s): NGUYEN, HOAI AN D
• Application Number:
  US14/084,978
• Publication Number:
  US 20140176164A1
• Time in Patent Office: 671 Days
• Field of Search: 324/709, 324/691, 324/649, 324/600
• US Class Current: 1/1
• CPC Class Codes: A46B 2200/3073 Brush for cleaning specific unusual places not otherwise covered, e.g. gutters, golf clubs, tops of tin cans, corners
• CPC Class Codes: A46B 9/028 Bristle profile, the end of the bristle defining a surface other than a single plane or deviating from a simple geometric form, e.g. cylinder, sphere or cone
• CPC Class Codes: G01B 11/0616 of coating
• CPC Class Codes: G01D 11/30 Supports specially adapted for an instrument; Supports specially adapted for a set of instruments
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825
• CPC Class Codes: G01R 1/20 Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments
• CPC Class Codes: G01R 1/22 Tong testers acting as secondary windings of current transformers
• 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
• CPC Class Codes: G01R 19/0084 measuring voltage only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks
• CPC Class Codes: G01R 31/086 in power transmission or distribution networks, i.e. with interconnected conductors
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: G01W 1/14 Rainfall or precipitation gauges measuring volume in general G01F
• CPC Class Codes: H01F 27/02 Casings
• CPC Class Codes: H01F 27/22 Cooling by heat conduction through solid or powdered fillings
• CPC Class Codes: H01F 38/30 Constructions
• CPC Class Codes: H01R 4/28 Clamped connections, spring connections made by means of terminals specially adapted for contact with, or insertion into, printed circuits H01R12/00
• CPC Class Codes: H02G 1/02 for overhead lines or cables
• CPC Class Codes: H04N 23/51 : Housings
• CPC Class Codes: H04N 7/181 : for receiving images from a plurality of remote sources
• CPC Class Codes: Y02E 10/50 : Photovoltaic [PV] energy
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing

Abstract

A device for measuring a voltage of an electric power line conductor of a power system according to an exemplary aspect of the present disclosure includes, among other things, a first electrically conductive housing configured to be installed on a first power line conductor and a first virtual grounding member configured to electrically ground a first housing to a first power line conductor voltage. A first measuring resistor is electrically connected between the first virtual grounding member and an electrically isolated lead wire, the electrically isolated lead wire is electrically connected to a first voltage dropping device, the first voltage dropping device is configured to be electrically connected to a second power line conductor. A sensor electronics module is configured to measure a voltage drop across the first measuring resistor, the voltage drop being directly proportional to the voltage between the first power line conductor and the second power line conductor.

Claims

1. A device for measuring a voltage of an electric power line conductor of a power system comprising:

a first electrically conductive housing configured to be installed on a first power line conductor;

a first virtual grounding member configured to electrically ground a first housing to a first power line conductor voltage;

a first measuring resistor electrically connected between the first virtual grounding member and an electrically isolated lead wire, the electrically isolated lead wire electrically connected to a first voltage dropping device, the first voltage dropping device configured to be electrically connected to a second power line conductor; and

a sensor electronics module configured to measure a voltage drop across the first measuring resistor, the voltage drop being directly proportional to the voltage between the first power line conductor and the second power line conductor.

2. The device of claim 1, including a power supply electronics module configured to provide power to the sensor electronics module, the sensor electronics module is configured to process voltage data representing a voltage drop output across the first measuring resistor and transmit the voltage data to a remote location with a transmitter and receiver unit.

3. The device of claim 2 wherein the power supply electronics module includes a magnetic core configured to surround the first power line conductor including a secondary winding configured to deliver power to the power supply electronics module.

4. The device of claim 3 wherein the magnetic core includes a first magnetic core and a second magnetic core configured to surround the first power line conductor.

5. The device of claim 1 including an electrical circuit interrupting device configured to isolate the first voltage dropping device from the first measuring resistor when the voltage dropping device fails.

6. The device of claim 1 wherein the first measuring resistor is non-inductive and non-capacitive and the first voltage dropping device includes at least one non-inductive and non-capacitive component.

7. The device of claim 1 wherein the voltage dropping device includes a surge block configured to limit current flow.

8. The device of claim 1 wherein the voltage dropping device includes electrically conductive fittings for attaching an electrically conductive jumper between the electrically isolated lead wire and the voltage dropping device.

9. The device of claim 1 including a clamp connected to a fitting on the one end of the voltage dropping device to facilitate installation on the second power line conductor and a stirrup connected to the other end fitting of the first voltage dropping device to facilitate installing an electrically conductive jumper with the clamp to the electrically isolated lead wire.

10. The device of claim 1 wherein the voltage dropping device includes an electrically conductive fitting attached directly to the electrically isolated lead wire which is electrically insulated from the first housing on a first end and a second end of the said voltage dropping device includes an electrically conductive fitting attached to an overcurrent protective device, the overcurrent protective device is connected via an electrically conductive jumper to at least one of the second power line conductor, a neutral conductor, or an earth ground conductor.

11. The device of claim 10 wherein the electrically conductive fitting includes a sealed electrical insulator and a valve configured to create a negative pressure within the sealed electrical insulator.

12. The device of claim 1 wherein the electrically isolated lead wire is connected to the first measuring resistor on a first end to an electrically conductive stud on a second end, the electrically conductive stud is electrically isolated from the first housing, and an electrically conductive hinge post is threaded onto the stud to support a first side of a flexible electrically conductive stirrup assembly, and a second electrically conductive stud electrically isolated from the first housing and a second electrically conductive hinge post support a second side of the stirrup assembly.

13. The device of claim 12, wherein the stud, the second stud, the hinge post, and the second hinge post are electrically isolated from the first housing with a plurality of electrical insulators.

14. The device of claim 12, including a clamp connecting one end of an electrically conductive jumper to the stirrup assembly.

15. The device of claim 14, wherein the jumper includes an electrically conductive internal wire and an electrically insulating cover, a first hotline clamp is attached on a first end of the jumper and a second hotline clamp attached on a second end of the jumper, the first hotline clamp is attached to the flexible stirrup assembly and the second hotline clamp is attached to a stirrup on the first voltage dropping device.

16. The device of claim 15 including an electrical interrupting device configured to isolate the voltage dropping device from the measuring resistor when an excessive current flows through the first voltage dropping device and the first measuring resistor to prevent a phase to phase, phase to neutral, or phase to earth ground fault on the power system.

17. The device of claim 1 wherein the electrically isolated lead wire is electrically isolated from said first housing and connected to the measuring resistor on a first end and connected to an electrically conductive stud on a second end, the electrically conductive stud is electrically isolated from the housing and includes an electrically conductive ring connector threaded on the electrically conductive stud for attachment of a hotline clamp to the electrically conductive ring connector.

18. The device of claim 1 wherein the electrically isolated lead wire is isolated from the housing and connected to the first measuring resistor on a first end and to an electrically conductive stud on a second end, the electrically conductive stud is electrically isolated from the housing and an electrically conductive hinge post threaded onto the stud, a jumper attached to the hinge post.

19. The device of claim 1 including a “

C”

loop coil configured to measure a current waveform and a measured angle between a measured line current phasor and a measured voltage phasor.

20. The system of claim 1 wherein the power system is a single phase delta connected ungrounded system.

21. The system of claim 20 includes:

a first lightning arrester configured to be installed near the first housing, a first arrester lead wire configured to be connected to the first power line conductor, and a first arrester ground lead configured to be connected to an earth grounded conductor; and

a second lightning arrester including a second lightning arrester lead wire configured to be connected to the second power line conductor and a second arrester ground lead is configured to be connected to an earth grounded conductor.

22. The system of claim 20, wherein the first housing includes:

a “

C”

loop coil configured to measure a line current in the first power line conductor.

23. The system of claim 20 wherein a lightning stroke voltage is measured between the first power line conductor and the second power line conductor.

24. The system of claim 1 wherein the electric power system is a three phase delta connected ungrounded system and includes:

a second housing having a second housing configured to be installed on the second power line conductor and a second voltage dropping device configured to be installed on a third power line conductor; and

a third housing having a third housing configured to be installed on a third power line conductor and a third voltage dropping device connected to the first power line conductor for measuring three phase to phase voltages.

25. The system of claim 24 wherein a lightning stroke voltage is measured between the first power line conductor, the second power line conductor, and the third power line conductor.

26. The system of claim 24 wherein the first housing includes a first lightning arrester configured to be attached near the first housing with a first arrester lead wire configured to be connected to the first power line conductor and a first arrester ground lead configured to be connected to an earth ground conductor, the second housing includes a second lightning arrester configured to be attached near the second housing with a second arrester lead wire configured to be connected to the second power line conductor and a second arrester ground lead configured to be connected to an earth ground conductor, and a third lightning arrester configured to be attached near the third housing with a third arrester lead wire configured to be connected to the third power line conductor and a third arrester ground lead configured to be connected to the earth ground conductor for measuring the three phase to phase voltages.

27. The system of claim 24 wherein the first housing includes a first “

C”

loop coil for measuring a first line current in the first power line conductor and the second housing includes a second “

C”

loop coil for measuring a second line current in the second power line conductor, and the third housing includes a third “

C”

loop coil for measuring a third line current in the third power line conductor.

28. A device for measuring the voltage of an electric power line conductor for a power system comprising:

a first electrically conductive housing configured to be installed on a first power line conductor;

a first virtual grounding member configured to electrically ground the first housing to a first power line conductor voltage;

a first measuring resistor electrically connected between the first virtual ground member and an electrically isolated lead wire, the electrically isolated lead wire electrically connected to a first voltage dropping device, the first voltage dropping device configured to be electrically connected to an earth grounded neutral conductor; and

a sensor electronics module configured to measure a voltage drop across the first measuring resistor, the voltage drop being directly proportional to a voltage between the first power line conductor and the earth grounded neutral conductor.

29. The system of claim 28, wherein the power system is a single phase multi-grounded wye connected system and the first housing includes:

a first lightning arrester configured to be installed near the first housing having a first arrestor lead wire configured to be connected to the first power line conductor, the first voltage dropping device attached to a grounding stud of the first lightning arrester, a first ground lead of the first lightning arrester is configured to be connected to the earth grounded neutral conductor for measuring the voltage between the first power line conductor and the earth grounded neutral conductor.

30. The system of claim 28, wherein the first voltage dropping device is configured to be connected to the earth grounded neutral conductor and to the measuring resistor of the first housing for measuring the voltage between the first power line conductor and the earth grounded neutral conductor.

31. The system of claim 28, wherein the power system is a single phase multi-grounded wye connected system and wherein the first voltage dropping device is configured to be connected to the earth grounded neutral conductor and the first measuring resistor for measuring the voltage between the first power line conductor and the earth grounded neutral conductor and the first housing includes a first “

C”

loop coil for measuring a phase current in the first power line conductor.

32. The system of claim 30 wherein a lightning stroke voltage is measured between the first power line conductor and the earth grounded neutral conductor.

33. The system of claim 28 wherein the power system is a three phase multi-grounded wye connected system and the first housing is configured to be mounted on the first power line conductor having the first voltage dropping device configured to be connected to the first measuring resistor for measuring the voltage between the first power line conductor and the earth grounded neutral conductor;

a second housing is configured to be mounted on the second power line conductor having a second voltage dropping device configured to be connected to a second measuring resistor for measuring a voltage between the second power line conductor and the earth grounded neutral conductor; and

a third housing is configured to be mounted on a third power line conductor having a third voltage dropping device configured to be connected to a third measuring resistor for measuring a voltage between the third power line conductor and the earth grounded neutral conductor.

34. The system of claim 33 including:

a first lightning arrester configured to be installed near the first housing having a first arrester lead wire configured to be connected to the first power line conductor and a first arrester ground lead connected to the first voltage dropping device and configured to be connected to the earth grounded neutral conductor and the first measuring resistor of the first housing for measuring the voltage between the first power line conductor and the earth grounded neutral conductor;

a second lightning arrester configured to be installed near the second housing having a second arrester lead wire configured to be connected to the second power line conductor and a second arrester ground lead connected to the second voltage dropping device and configured to be connected to the earth grounded neutral conductor and the second measuring resistor of the second housing for measuring the voltage between the second power line conductor and the earth grounded neutral conductor and

a third lightning arrester configured to be installed near the third housing with a third arrester lead wire configured to be connected to the third power line conductor and a third arrester ground lead connected to the third voltage dropping device and configured to be connected to the earth grounded neutral conductor and the third measuring resistor of the third housing for measuring the voltage between the third power line conductor and the earth grounded neutral conductor.

35. The system of claim 34 wherein the first housing includes a first “

C”

loop coil for measuring the phase current in the first power line conductor, the second housing includes a second “

C”

loop coil for measuring the phase current in the second power line conductor, and the third housing including a third “

C”

loop coil for measuring the phase current in the third power line conductor.

36. A device for measuring the voltage of an electric power line conductor for a power system comprising:

a first electrically conductive housing configured to be installed on a first power line conductor;

a first virtual grounding member configured to electrically ground the first housing to a first power line conductor voltage;

a first measuring resistor electrically connected between the first virtual ground member and an electrically isolated lead wire, the electrically isolated lead wire electrically connected to a first voltage dropping device, the first voltage dropping device configured to be electrically connected to an ungrounded neutral conductor; and

a sensor electronics module configured to measure a voltage drop across the first measuring resistor, the voltage drop being directly proportional to a voltage between the first power line conductor and the ungrounded neutral conductor.

37. The system of claim 36, wherein the power system is a single phase ungrounded wye connected system and the first housing includes:

a first lightning arrester configured to be installed near the first housing having a first arrester lead wire configured to be connected to the first power line conductor with an arrester ground lead connected to earth ground.

38. The system of claim 36 wherein the power system is a single phase ungrounded wye connected system and the first voltage dropping device is configured to be connected to the ungrounded neutral conductor for measuring the voltage between the first power line conductor and the ungrounded neutral conductor, and the first housing includes a first “

C”

loop coil for measuring a phase current in the first power line conductor.

39. The system of claim 38 wherein a lightning stroke voltage is measured between the first power line conductor and the ungrounded neutral conductor.