Impedance shift analysis to predict failures in an electrical power distribution network

Patent metadata

Field	Value
Publication number	US-10439434-B2
Application number	US-201715454556-A
Country	US
Kind code	B2
Filing date	Mar 9, 2017
Priority date	Mar 9, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Embodiments of the present invention provide for impedance shift analysis for failure prediction in an electrical power distribution network. In an embodiment of the invention, the method includes receiving a sequence of electrical measurements indicative of an impedance measured for a segment of an electrical power distribution network over a period of time. Then, a set of impedance measurements is computed for the period of time and the set of impedance measurements is organized into a distribution correlating each one of the impedance measurement with a corresponding computed current measurement. A trend line for the distribution is identified and a slope computed of the trend line. Finally, on condition that the slope exceeds a threshold steepness, an impending failure in the segment is determined and a notification transmitted over a computer communications network to an end user requesting physical inspection of the segment.

First claim

We claim:

1. A method for impedance shift analysis for failure prediction in an electrical power distribution network, the method comprising:
receiving in memory of a computer, a sequence of electrical measurements indicative of an impedance measured for a segment of an electrical power distribution network over a period of time;
computing by a processor of the computer a set of impedance measurements for the period of time, organizing the set of impedance measurements into a distribution correlating each one of the impedance measurement with a corresponding computed current measurement, identifying a trend line for the distribution and computing a slope of the trend line; and,
on condition that the slope exceeds a threshold steepness, determining by the processor of the computer that a failure is impending in the segment and transmitting a notification over a computer communications network to an end user requesting physical inspection of the segment.

2. The method of claim 1 , wherein the sequence of electrical measurements are voltage and kilowatt hour values received over the period of time from an upstream electrical meter disposed at a portion of the segment closest to a sub-station and from a downstream electrical meter disposed at a portion of the segment furthers from the sub-station.

3. The method of claim 2 further comprising determining if both the upstream and downstream electrical meters have a load associated therewith selecting an alternate meter with a load associated therewith to replace one of the upstream or downstream electrical meters if one of the upstream or downstream electrical meters are determined not to have a load associated therewith.

4. The method of claim 2 , wherein each impedance value for the segment is a quotient of a difference between contemporaneously measured voltage values at the upstream and downstream electrical meters, and a computed current contemporaneously measured for the segment.

5. The method of claim 4 , wherein the current is derived from the kilowatt hour values provided by the upstream and downstream meters.

6. The method of claim 2 , wherein the notification requests dispatch to the upstream-downstream electrical meter pair encompassing a particular segment.

7. The method of claim 2 , wherein the upstream electrical meter and the downstream electrical meter communicate over a mesh network coupled to the computer.

8. An electrical power distribution network configured for impedance shift analysis for failure prediction, the network comprising:
a computer comprising memory and at least one processor and hosting the execution of a failure prediction module;
a substation distributing electrical power;
a feeder having a feeder segment with an upstream end closest to the substation and a downstream end further from the substation than the upstream end, the feeder segment demonstrating a measurable impedance; and,
a multiplicity of electrical meters coupled to the feeder and measuring electrical consumption at respective premises end points of the network, the meters periodically reporting to the failure prediction module a sequence of electrical measurements indicative of an impedance measured for a segment of an electrical power distribution network;
the failure prediction module comprising program code that when executed in the computer computes a set of impedance measurements for a period of time, organizes the set of impedance measurements into a distribution correlating each one of the impedance measurement with a corresponding computed current measurement, identifies a trend line for the distribution and computes a slope of the trend line, and on condition that the slope exceeds a threshold steepness, determines that a failure is impending in the feeder segment and transmits a notification over a computer communications network to an end user requesting physical inspection of the feeder segment.

9. The system of claim 8 , wherein the sequence of electrical measurements are voltage and kilowatt hour values received from an upstream one of the electrical meters disposed at the upstream end and from a downstream one of the electrical meters disposed at the downstream end.

10. The system of claim 9 , wherein each impedance value for the segment is a quotient of a difference between contemporaneously measured voltage values at the upstream and downstream electrical meters, and a computed current contemporaneously measured for the segment.

11. The system of claim 10 , wherein the current is derived from the kilowatt hour values provided by the upstream and downstream meters.

12. The system of claim 9 , wherein the notification requests dispatch to the upstream-downstream pair of the electrical meters encompassing the particular feeder segment.

13. The system of claim 9 , wherein the upstream one of the electrical meters and the downstream one of the electrical meters communicate over a mesh network coupled to the computer.

14. A computer program product for impedance shift analysis for failure prediction in an electrical power distribution network, the computer program product comprising a computer readable storage, non-transitory medium having program instructions embodied therewith, the program instructions executable by a device to cause the device to perform a method comprising:
receiving a sequence of electrical measurements indicative of an impedance measured for a segment of an electrical power distribution network over a period of time;
computing a set of impedance measurements for the period of time, organizing the set of impedance measurements into a distribution correlating each one of the impedance measurement with a corresponding computed current measurement, identifying a trend line for the distribution and computing a slope of the trend line; and,
on condition that the slope exceeds a threshold steepness, determining by the processor of the computer that a failure is impending in the segment and transmitting a notification over a computer communications network to an end user requesting physical inspection of the segment.

15. The computer program product of claim 14 , wherein the sequence of electrical measurements are voltage and kilowatt hour values received from an upstream electrical meter disposed at a portion of the segment closest to a sub-station and from a downstream electrical meter disposed at a portion of the segment furthers from the sub-station.

16. The computer program product of claim 15 further comprising determining if both the upstream and downstream electrical meters have a load associated therewith; and selecting an alternate meter with a load associated therewith to replace one of the upstream or downstream electrical meters if one of the upstream or downstream electrical meters are determined not to have a load associated therewith.

17. The computer program product of claim 14 , wherein each impedance value for the segment is a quotient of a difference between contemporaneously measured voltage values at the upstream and downstream electrical meters, and a computed current contemporaneously measured for the segment.

18. The computer program product of claim 16 , wherein the current is derived from the kilowatt hour values provided by the upstream and downstream meters.

19. The computer program product of claim 15 , wherein the notification requests dispatch to the upstream-downstream electrical meters encompassing the particular feeder segment.

20. The computer program product of claim 15 , wherein the upstream electrical meter and

Assignees

• Florida Power & Light Co
• Windlogics Inc

Inventors

• Aleman Guillermo
• Perez Eliud
• Epel Aaron J G

Classifications

• H02H3/40

  responsive to ratio of voltage and current · CPC title

• H02H3/44

  responsive to the rate of change of electrical quantities · CPC title

• H02J2103/30

  Simulating, planning, modelling, reliability check or computer assisted design [CAD] of electric power networks · CPC title

• H02J13/333

  the equipment forming part of substations · CPC title

• H02J13/1321 Primary

  using a wired telecommunication network or a data transmission bus · CPC title