METHODS AND APPARATUS FOR DETERMINING CONDITIONS OF POWER LINES

• US 20130054183A1
• Filed: 07/11/2012
• Published: 02/28/2013
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: Aclara Technologies LLC (Hubbell, Inc.)
• Original Assignee: Tollgrade Communications Incorporated (Enghouse Systems Limited)
• Inventors: Afzal, Muhammad A., Smith, Roger A., Ross, Rebecca, Pothamsetty, Venkat
• Granted Patent: US 9,647,454 B2
• Time in Patent Office: Days
• US Class Current: 702/141
• 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: H02J 13/00 Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00017 using optical fiber
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 3/00125 Transmission line or load transient problems, e.g. overvoltage, resonance or self-excitation of inductive loads H02J3/01 takes precedence
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 10/52 Outage or fault management, e.g. fault detection or location
• CPC Class Codes: Y04S 40/124 using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

Techniques for determining conditions of power lines in a power distribution system based on measurements collected by a plurality of sensor units deployed in the power distribution system. Techniques include obtaining first transformed data associated with a first set of one or more measurements collected by a first sensor unit in the plurality of sensor units and second transformed data associated with a second set of one or more measurements collected by a second sensor unit in the plurality of sensor units, and determining, by using at least one processor and based at least in part on one or more features calculated from the first transformed data and the second transformed data, at least one condition of at least one power line in the power distribution system.

Claims

1. A method for determining conditions of power lines in a power distribution system based on measurements collected by a plurality of sensor units deployed in the power distribution system, the method comprising:

obtaining first transformed data associated with a first set of one or more measurements collected by a first sensor unit in the plurality of sensor units and second transformed data associated with a second set of one or more measurements collected by a second sensor unit in the plurality of sensor units; and

determining, by using at least one processor and based at least in part on one or more features calculated from the first transformed data and the second transformed data, at least one condition of at least one power line in the power distribution system.

2. The method of claim 1, wherein the first transformed data comprises a first plurality of transform coefficient values, the second transformed data comprises a second plurality of transform coefficient values, and wherein:

obtaining the first transformed data comprises applying a shift-invariant transformation to the first set of measurements to produce the first plurality of transform coefficient values, and

obtaining the second transformed data comprises applying the shift-invariant transformation to the second set of measurements to produce the second plurality of transform coefficient values.

3. The method of claim 1, wherein the first transformed data comprises a first plurality of transform coefficient values, the second transformed data comprises a second plurality of transform coefficient values, and wherein:

obtaining the first transformed data comprises receiving the first plurality of transform coefficient values, wherein the first plurality of transform coefficient values were calculated by applying a shift-invariant transformation to the first set of measurements; and

obtaining the second transformed data comprises receiving the second plurality of transform coefficient values, wherein the second plurality of transform coefficient values were calculated by applying a shift-invariant transformation to the second set of measurements.

4. The method of claim 2, wherein determining the at least one condition comprises:

calculating a first feature from a first subset of transform coefficient values in the first plurality of transform coefficient values and a second feature from a corresponding subset of transform coefficient values in the second plurality of transform coefficient values; and

determining the at least one condition based on the first and second features.

5. The method of claim 2, wherein obtaining the first feature comprises calculating at least a first energy from values in the first plurality of transform coefficient values.

6. The method of claim 2, wherein the shift-invariant transformation is a shift-invariant multi-resolution transformation such that the first plurality of transform coefficients values comprises at least a first set of transform coefficient values associated with a first resolution and a second set of transform coefficient values associated with a second resolution, wherein the first resolution is different from the second resolution, and wherein determining the at least one condition comprises:

determining a first condition based on one or more features obtained using only coefficient values in the first set of transform coefficient values and corresponding transform coefficient values in the second plurality of transform coefficient values.

7. The method of claim 2 or 3, wherein applying the shift-invariant transformation to the first data comprises applying a shift-invariant wavelet transformation to the first set of measurements.

8. The method of claim 1, further comprising identifying information indicative of a location of the at least one condition along the at least one power line based on location order of the first sensor unit and the second sensor unit along a power line with respect to a substation.

9. The method of claim 1, wherein determining the at least one condition comprises identifying a type of the at least one condition as a type of condition associated with animal contact with the at least one power line, lightning strike, tree contact with the at least one power line, ice on the at least one power line, sag in the at least one power line, stretch in the at least one power line, or oscillation of the at least one power line.

10. The method of claim 1, wherein the first sensor unit and the second sensor unit are coupled to different power line segments.

11. The method of claim 1, wherein determining the at least one condition comprises detecting a current need for maintenance of the at least one power line and/or predicting a need for future maintenance of the at least one power line.

12. A management system for a power distribution system comprising a plurality of power lines, a plurality of sensor units configured to collect measurements about power lines in the plurality of power lines, wherein the plurality of sensor units includes a first sensor unit and a second sensor unit adapted to be coupled to a different power line from the first sensor unit, the management system comprising:

at least one controller configured to;

obtain first transformed data associated with a first set of one or more measurements collected by the first sensor unit and second transformed data associated with a second set of one or more measurements collected by the second sensor unit; and

determine, based at least in part on one or more features calculated from the first transformed data and the second transformed data, at least one condition of at least one power line in the power distribution system.

13. The management system of claim 12, wherein the first transformed data comprises a first plurality of transform coefficient values, the second transformed data comprises a second plurality of transform coefficient values, and wherein the at least one controller is configured to:

obtain the first transformed data by applying a shift-invariant transformation to the first set of measurements to produce the first plurality of transform coefficient values, and

obtain the second transformed data by applying the shift-invariant transformation to the second set of measurements to produce the second plurality of transform coefficient values.

14. The management system of claim 12, wherein the first transformed data comprises a first plurality of transform coefficient values, the second transformed data comprises a second plurality of transform coefficient values, and wherein the at least one controller is configured to:

obtain the first transformed data by receiving the first plurality of transform coefficient values, wherein the first plurality of transform coefficient values were calculated by applying a shift-invariant transformation to the first set of measurements; and

obtain the second transformed data by receiving the second plurality of transform coefficient values, wherein the second plurality of transform coefficient values were calculated by applying a shift-invariant transformation to the second set of measurements.

15. The management system of claim 13, wherein the first plurality of transform coefficients values comprises at least a first set of transform coefficient values associated with a first resolution and a second set of transform coefficient values associated with a second resolution, wherein the first resolution is different from the second resolution, and wherein the at least one controller is configured to determine the presence of the at least one condition by:

determining a first condition based on one or more features obtained using only coefficient values in the first set of transform coefficient values and corresponding transform coefficient values in the second plurality of transform coefficient values.

16. The management system of claim 13, wherein the at least one controller is configured to apply the multi-resolution shift-invariant transformation to the first set of measurements by applying a stationary wavelet transform or a continuous wavelet transform to the first set of measurements.

17. The management system of claim 12, wherein determining the at least one condition comprises identifying a type of the at least one condition as a type of condition associated with animal contact with the at least one power line, lightning strike, tree contact with the at least one power line, ice on the at least one power line, sag in the at least one power line, stretch in the at least one power line, or oscillation of the at least one power line.

18. A sensor unit configured to be coupled to a power line, the sensor unit configured to:

collect a set of one or more measurements from the power line,

apply a shift-invariant transformation to the set of one or more measurements to produce a first plurality of transform coefficient values, and

transmit transform coefficient values in the first plurality of transformed coefficient values.

19. The sensor unit of claim 18, wherein the sensor unit is configured to apply the shift-invariant transformation to the set of one or more measurements by applying a stationary wavelet transform or a continuous wavelet transform to the set of one or more measurements.

20. The sensor unit of claim 18, wherein the sensor unit is configured to collect the set of one or more measurements by using an inclinometer and/or an accelerometer.

21. At least one tangible computer readable storage medium storing processor-executable instructions that, when executed by at least one processor, cause the at least one processor to perform a method for determining conditions of power lines in a power distribution system based on measurements collected by a plurality of sensor units deployed in the power distribution system, the method comprising:

obtaining first transformed data associated with a first set of one or more measurements collected by a first sensor unit in the plurality of sensor units and second transformed data associated with a second set of one or more measurements collected by a second sensor unit in the plurality of sensor units; and

determining, based at least in part on one or more features calculated from the first transformed data and the second transformed data, at least one condition of at least one power line in the power distribution system.

22. The at least one tangible computer readable storage medium of claim 21, wherein the first transformed data comprises a first plurality of transform coefficient values, the second transformed data comprises a second plurality of transform coefficient values, and wherein:

obtaining the first transformed data comprises applying a shift-invariant transformation to the first set of measurements to produce the first plurality of transform coefficient values, and

obtaining the second transformed data comprises applying the shift-invariant transformation to the second set of measurements to produce the second plurality of transform coefficient values.

23. The at least one tangible computer readable storage medium of claim 21, wherein the first transformed data comprises a first plurality of transform coefficient values, the second transformed data comprises a second plurality of transform coefficient values, and wherein:

obtaining the first transformed data comprises receiving the first plurality of transform coefficient values, wherein the first plurality of transform coefficient values were calculated by applying a shift-invariant transformation to the first set of measurements; and

obtaining the second transformed data comprises receiving the second plurality of transform coefficient values, wherein the second plurality of transform coefficient values were calculated by applying a shift-invariant transformation to the second set of measurements.

24. The at least one tangible computer readable storage medium of claim 22, wherein determining the at least one condition comprises:

calculating a first feature from a first subset of transform coefficient values in the first plurality of transform coefficient values and a second feature from a corresponding subset of transform coefficient values in the second plurality of transform coefficient values; and

determining the at least one condition based on the first and second features.

25. The at least one tangible computer readable storage medium of claim 22, wherein obtaining the first feature comprises calculating at least a first energy from values in the first plurality of transform coefficient values.

26. The at least one tangible computer readable storage medium of claim 23, wherein applying the shift-invariant transformation to the first data comprises applying a shift-invariant wavelet transformation to the first set of measurements.

27. The at least one tangible computer readable storage medium of claim 21, further the method further comprises identifying information indicative of a location of the at least one condition along the at least one power line based on location order of the first sensor unit and the second sensor unit along a power line with respect to a substation.

28. The at least one tangible computer readable storage medium of claim 21, wherein determining the at least one condition comprises identifying a type of the at least one condition as a type of condition associated with animal contact with the at least one power line, lightning strike, tree contact with the at least one power line, ice on the at least one power line, sag in the at least one power line, stretch in the at least one power line, or oscillation of the at least one power line.