Power line sag monitor

• US 6,523,424 B1
• Filed: 10/20/2000
• Issued: 02/25/2003
• Est. Priority Date: 10/07/1998
• Status: Expired due to Fees

• Current Assignee: Ali Nourai, Ray M. Hayes
• Original Assignee: Ali Nourai, Ray M. Hayes
• Inventors: Nourai, Ali, Hayes, Ray M.
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US09/692,624
• Time in Patent Office: 858 Days
• Field of Search: 738/623.91, 734/93, 324/127, 340/870.16
• US Class Current: 73/862.391
• CPC Class Codes: G01C 9/00 Measuring inclination, e.g. by clinometers, by levels
• CPC Class Codes: H02G 1/04 for mounting or stretching
• CPC Class Codes: H02G 7/02 Devices for adjusting or maintaining mechanical tension, e.g. take-up device

Abstract

An accelerometer properly positioned in conjunction with an energized electrical conductor produces an output that is dependent on conductor'"'"'s inclination angle in real time where the inclination angle is then used to calculate the sag of the conductor. A transmitter is used to communicate this information in real time to a central location such that up to optimal or maximum power transmission is feasible through the conductor while maintaining safe clearance from the ground. This allows for close monitoring of thermal expansion resulting from increased load as well as varying environmental conditions.

Claims

1. A sag monitor system for use on a span of a power conductor, the span being a section of the power conductor suspended between a pair of transmission towers, the sag monitor system for monitoring sag therein during power transmission, the sag monitor system comprising:

an accelerometer positionable adjacent and parallel to the power conductor approximate one of its suspension points, the accelerometer outputting a voltage correlated to an angle of inclination of the conductor;

a transmitter electrically connected to the accelerometer for reading the voltage output by the accelerometer and transmitting signals indicative of the voltage output by the accelerometer;

a remote processor including a receiver for receiving signals indicative of the voltage output of the accelerometer, and calculating the sag in the power conductor based upon these signals, wherein multiple accelerometers are each positionable adjacent to the power conductor on different spans thereof whereby each accelerometer has an associated transmitter electrically connected thereto for reading the voltage output by that accelerometer and transmitting signals indicative of the voltage output by that accelerometer, and where the remote processor receives signals indicative of the voltage output by all of the multiple accelerometers whereby such signals each is identifiable to its respective accelerometer, and further comprising a transceiver for use with one or more accelerometers, the transceiver for receiving voltage output signals from the transmitters connected to each of the accelerometers and transmitting a long distance signal indicative of the voltage outputs to the remote processor, and the multiple accelerometers are aligned in series whereby voltage output signals from each accelerometer is communicated via other accelerometers until such output signals are received by the transceiver and transmitted as the long distance signal indicative of the voltage outputs to the remote processor.

2. The sag monitor system of claim 1 wherein each accelerometer is housed in a housing fitted over the power conductor where the housing further includes the respective transmitter.

3. The sag monitor system of claim 2 wherein each housing is a corona free housing.

4. The sag monitor system of claim 1 wherein each accelerometer is an inclinometer, and the transceiver is remote from the accelerometers and is solar powered.

5. The sag monitor system of claim 1 wherein the accelerometer and transmitter are powered by a magnetic field provided by the power conductor.

6. The sag monitor system of claim 1 wherein the remote processor calculates the sag from the output signals received.

7. The sag monitor system of claim 6 wherein the angle of inclination is used to calculate the sag based upon the equation that the sag equals 0.24492 multiplied by the span which is multiplied by the tangent of the inclination angle when the towers are at approximately the same elevation and the land between the towers is relatively flat.

8. The sag monitor system of claim 1 wherein the output is used to calculate the angle of inclination based upon a calibration equation correlating that for a particular accelerometer the output varies with the angle of inclination.

9. The sag monitor of claim 1 wherein each accelerometer measures the angle that the power conductor is from horizontal by approximating an inclination angle at the respective suspension point.

10. The sag monitor of claim 1 further comprising a microprocessor which approximates/calculates the sag in the power line based upon the inclination angle.

11. A sag monitor for use on a first span of a power conductor suspended between a pair of transmission towers, the sag monitor for monitoring the sag therein during power transmission, the sag monitor comprising:

a housing positionable adjacent to a power conductor approximate one of its suspension points; and

a plurality of accelerometers affixed within the housing, each individual accelerometer providing a voltage output indicative of an angle the power conductor is from the horizontal, wherein all of the accelerometers within the housing are approximately within the same normal plane of the power conductor, wherein the sag is calculated as about 0.25 multiplied by the span multiplied by the tangent of the inclination angle when the towers are at approximately the same elevation and the land therebetween is relatively flat.

12. The sag monitor of claim 11 wherein each accelerometer measures the angle that the power conductor is from horizontal by approximating an inclination angle at the respective suspension point.

13. The sag monitor of claim 11 further comprising a microprocessor which approximates/calculates the sag in the power line based upon the inclination angle.

14. The sag monitor of claim 11 wherein a second sag monitor is used on a second span of the power conductor between two other pair of transmission towers, and the sag monitor and the second sag monitor each include a transmitter for sending signals indicative of the output of the respective accelerometer to a remote receiver.

15. The sag monitor of claim 14 further comprising a transceiver positioned approximate yet separate from the sag monitor and second sag monitor for receiving the signals from the accelerometers indicative of the output thereof and transmitting such signals to the remote receiver.

16. The sag monitor of claim 15 further comprising a microprocessor which approximates/calculates the sag in the power line based upon the inclination angle.

17. The sag monitor of claim 16, wherein the microprocessor uses the voltage output to calculate the angle of inclination based upon a calibration equation correlating that for a particular accelerometer the output voltage varies with the angle of inclination.

18. The sag monitor of claim 15 wherein each accelerometer is an inclinometer, and the transceiver is remote from the accelerometers and is solar powered.

19. The sag monitor of claim 15, wherein the accelerometers of the sag monitor and the second sag monitor are aligned in series whereby voltage output signals from each accelerometer is communicated via other accelerometers until such output signals are received by the transceiver and transmitted as a long distance signal indicative of the voltage outputs to the remote processor.

20. The sag monitor of claim 15 wherein the accelerometer and transmitter are powered by a magnetic field provided by the power conductor.

21. The sag monitor of claim 11 wherein the housing is a corona free housing.

22. A sag monitor system for use on a span of a power conductor, the span being a section of the power conductor suspended between a pair of transmission towers, the sag monitor system for monitoring sag therein during power transmission, the sag monitor system comprising:

a first accelerometer being positionable adjacent and parallel to the power conductor approximate one of its suspension points, the first accelerometer outputting a voltage correlated to an angle of inclination of the power conductor;

a transmitter electrically connected to the first accelerometer for reading the voltage output by the first accelerometer and transmitting signals indicative of the voltage output by the first accelerometer;

a remote processor including a receiver for receiving signals indicative of the voltage output of the first accelerometer, and calculating the sag in the power conductor based upon these signals;

wherein multiple first accelerometers are each positionable adjacent to the power conductor on different spans thereof whereby each first accelerometer has an associated transmitter electrically connected thereto for reading the voltage output by the first accelerometer and transmitting signals indicative of the voltage output by the first accelerometer; and

where the remote processor receives signals indicative of the voltage output by all of the multiple first accelerometers whereby such signals each is identifiable to the respective first accelerometer, and further comprising a transceiver for use with one or more first accelerometers, the transceiver for receiving voltage output signals from the transmitters connected to each of the first accelerometers and transmitting a long distance signal indicative of the voltage outputs to the remote processor, and the remote processor calculates the sag from the output signals received, and the angle of inclination is used to calculate the sag based upon the equation that the sag equals about 0.24492 multiplied by the span which is multiplied by the tangent of the inclination angle when the towers are at approximately the same elevation and the land between the towers is relatively flat.

23. The sag monitor system of claim 22 wherein the system further comprises:

a housing adapted to be mounted onto a span of the power conductor, wherein the first accelerometer is affixed within the housing;

a second accelerometer affixed within the housing, the first and second accelerometers lying approximately within the same radial plane of the power conductor.

24. The sag monitor of claim 23 further comprising a microprocessor which approximates/calculates the sag in the power line based upon the inclination angle.

25. The sag monitor system of claim 23 wherein the housing is fitted over the power conductor and the housing further includes the respective transmitter.

26. The sag monitor system of claim 23 wherein the housing is a corona free housing.

27. The sag monitor system of claim 22 wherein one:

or more first accelerometers are located relatively close to the transceiver and the transceiver is adapted to receive voltage output signals from one or more of the relatively close first accelerometers and to transmit a long distance signal indicative of the voltage outputs of the one or more relatively close first accelerometers to the remote processor.

28. The sag monitor of claim 22 wherein each first accelerometer is an inclinometer and the transceiver is remote from the first accelerometer and is solar powered.

29. The sag monitor system of claim 22, wherein the multiple first accelerometers are aligned in series whereby voltage output signals from each first accelerometer are communicated via other first accelerometers until such output signals are received by the transceiver and transmitted as a long distance signal indicative of the voltage outputs to the remote processor.

30. The sag monitor system of claim 22 wherein the first accelerometer and transmitter are powered by a magnetic field provided by the power conductor.