System for detecting a falling electric power conductor and related methods

• US 10,153,635 B2
• Filed: 07/18/2016
• Issued: 12/11/2018
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: San Diego Gas & Electric Company (Sempra Energy)
• Original Assignee: San Diego Gas & Electric Company (Sempra Energy)
• Inventors: O'Brien, William, Udren, Eric A.
• Primary Examiner(s): Kaplan, Hal
• Application Number:
  US15/213,223
• Publication Number:
  US 20160329700A1
• Time in Patent Office: 876 Days
• Field of Search: 307125, 307130, 307131
• CPC Class Codes: H02H 3/02 Details
• CPC Class Codes: H02H 3/04 with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18
• CPC Class Codes: H02H 3/26 responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
• CPC Class Codes: H02H 3/265 responsive to phase angle between voltages or between currents
• CPC Class Codes: H02H 3/32 involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
• CPC Class Codes: H02H 3/325 involving voltage comparison H02H3/347 takes precedence
• CPC Class Codes: H02H 3/353 involving comparison of phase voltages
• CPC Class Codes: H02H 3/38 responsive to both voltage and current; responsive to phase angle between voltage and current
• CPC Class Codes: H02H 3/422 using homopolar quantities
• CPC Class Codes: H02H 3/44 responsive to the rate of change of electrical quantities
• CPC Class Codes: H02H 3/46 responsive to frequency deviations
• CPC Class Codes: H02H 3/48 responsive to loss of synchronism
• CPC Class Codes: H02H 7/261 involving signal transmission between at least two stations transmission of signals in general H02H1/0061
• CPC Class Codes: H02H 7/263 involving transmissions of measured values comparison of currents or voltages using pilot wires H02H3/30
• CPC Class Codes: H02H 7/28 for meshed systems
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• 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 10/22 Flexible AC transmission systems [FACTS] or power factor or reactive power compensating or correcting units

Abstract

Methods and systems for detecting a falling power line in a power transmission or distribution system are described. Electrical measurements at various points in the power distribution system are used to detect changes in a power line indicating that the conductor has broken or become disconnected. Upon detection, control mechanisms are used to deenergize the conductor while the conductor is falling and/or before it contacts the ground.

Claims

1. A control box for use in at least one of an electrical transmission system and a distribution system comprising:

a housing having an enclosure and enclosing a plurality of electronic circuitries;

a processor located in the housing and configured to;

receive a first signal from a first measuring device, the first measuring device configured to measure an electrical characteristic of a conductor at a location in the at least one of the electrical transmission system and the distribution system;

determine that a conductor break caused by the conductor falling has occurred based at least partly on the first signal from the first measuring device; and

emit a disconnect signal to one or more switching devices to deenergize the affected portion of the system before the conductor contacts the ground.

2. The control box of claim 1, wherein the processor is programmed to:

compare the measured electrical characteristic to a predetermined threshold value indicative of a falling conductor; and

determine that the conductor break has occurred based on the comparison.

3. The control box of claim 2, wherein the processor is programmed to determine that the conductor break is not caused by a short-circuit fault.

4. The control box of claim 2, wherein the measured electrical characteristic comprises voltage and the processor is programmed to determine that the voltage from the first measuring device is below the predetermined threshold value.

5. The control box of claim 1, wherein the processor is further configured to:

receive a second signal from a second measuring device, the second measuring device at a second location in the at least one of the electrical transmission system and the distribution system;

compare the first signal to the second signal, wherein the first signal comprises measurement information of the conductor from the first measuring device and the second signal comprises measurement information of the conductor from the second measuring device; and

determine that a conductor break caused by the conductor falling has occurred based at least partly on the comparison of the first signal and the second signal.

6. The control box of claim 5, wherein the measurement information from the first and second measuring devices comprises voltage information and comparing the first signal to the second signal comprises:

determining a voltage differential from the voltage information from the first measuring device and the voltage information from the second measuring device; and

comparing the voltage differential to a pre-set threshold value.

7. The control box of claim 1, wherein the first signal is representative of a problem with the conductor.

8. The control box of claim 7, wherein the one or more switching devices comprise multiple switching devices that are adjacent to the conductor having the problem.

9. The control box of claim 1, further comprising one or more ports associated with the housing for connecting at least one of wires, cables, input devices, and output devices.

10. The control box of claim 1, wherein the first signal comprises a trip signal.

11. The control box of claim 1, wherein the first signal comprises the electrical characteristic.

12. The control box of claim 1, wherein the electrical characteristic is current.

13. A method for detecting a falling conductor in at least one of an electrical transmission system and a distribution system, the method comprising:

receiving a first signal from a first measuring device, the first measuring device configured to measure an electrical characteristic of a conductor at a location in the at least one of the electrical transmission system and the distribution system;

determining that a conductor break caused by the conductor falling has occurred based at least partly on the first signal from the first measuring device; and

emitting a disconnect signal to one or more switching devices to deenergize the affected portion of the system before the conductor contacts the ground.

14. The method of claim 13, wherein determining whether the conductor break is caused by the conductor falling comprises:

receiving the measured electrical characteristic from the first measuring device;

comparing the measured electrical characteristic to a predetermined threshold value indicative of a falling conductor; and

determining that the conductor break has occurred based on the comparison.

15. The method of claim 14, wherein determining whether the conductor break is caused by the conductor falling further comprises determining that the conductor break is not caused by a short-circuit fault.

16. The method of claim 14, wherein the measured electrical characteristic comprises voltage and comparing the measured electrical characteristic to the predetermined threshold value comprises:

determining that the voltage from the first measuring device is below the predetermined threshold value.

17. The method of claim 13, further comprising:

receiving a second signal from a second measuring device, the second measuring device at a second location in the at least one of the electrical transmission system and the distribution system;

comparing the first signal to the second signal, wherein the first signal comprises measurement information of the conductor from the first measuring device and the second signal comprises measurement information of the conductor from the second measuring device; and

determining that a conductor break caused by the conductor falling has occurred based at least partly on the comparison of the first signal and the second signal.

18. The method of claim 17, wherein the measurement information from the first and second measuring devices comprises voltage information and comparing the first signal to the second signal comprises:

determining a voltage differential from the voltage information from the first measuring device and the voltage information from the second measuring device; and

comparing the voltage differential to a pre-set threshold value.

19. The method of claim 13, wherein the first signal indicates a problem with the conductor.

20. The method of claim 19, wherein the one or more switching devices comprise multiple switching devices that are adjacent to the conductor with the problem.

21. The method of claim 13, wherein the first signal comprises a trip signal.

22. The method of claim 13, wherein the first signal comprises the electrical characteristic.

23. The method of claim 13, wherein the electrical characteristic is current.

24. A non-transitory computer readable medium containing program instructions for detecting a falling conductor in at least one of an electrical transmission system and a distribution system, wherein execution of the program instructions by one or more processors of a computer system causes the one or more processors to perform the operations of:

receiving a signal from a measuring device, the measuring device configured to measure an electrical characteristic of a conductor at a location in the at least one of the electrical transmission system and the distribution system;

determining that a conductor break caused by the conductor falling has occurred based at least partly on the signal from the measuring device; and

emitting a disconnect signal to one or more switching devices to deenergize the affected portion of the system before the conductor contacts the ground.