Method and apparatus for legacy comparison

• US 7,761,248 B2
• Filed: 10/31/2007
• Issued: 07/20/2010
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: Power Measurement Ltd. (Schneider Electric SE)
• Original Assignee: Power Measurement Ltd. (Schneider Electric SE)
• Inventors: Lightbody, Simon H., Gunn, Colin N., Cowan, Peter C., Doig, Paul E., Hancock, Martin A., Forth, J. Bradford
• Primary Examiner(s): Lau; Tung S
• Assistant Examiner(s): Sun; Xiuquin
• Application Number:
  US11/981,172
• Publication Number:
  US 20080065335A1
• Time in Patent Office: 993 Days
• Field of Search: 702/61, 702/60, 702/59, 340/870.07, 340/870.27, 323/211
• US Class Current: 702/61
• CPC Class Codes: G01R 15/18 using inductive devices, e.g. transformers
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G01R 35/007 Standards or reference devices, e.g. voltage or resistance standards, "golden references"

Abstract

A line device monitors at least one power parameter of an electric power line and produces at least one representation thereof. The at least one representation is communicated to a microprocessor based device. The representation is compared with a measurement of the at least one power parameter produced by legacy instrumentation.

Claims

1. A system comprising:

a line device, coupled to the power line, that monitors at least one power parameter of the power line;

a microprocessor based device that receives a first indication of the at least one power parameter from the line device and a second indication of the at least one power parameter of the power line from legacy instrumentation coupled to the power line;

wherein the microprocessor based device compares the first indication of the at least one power parameter from the line device and the second indication of the at least one power parameter from the legacy instrumentation at substantially the same time period as the second indication of the at least one power parameter, yielding comparison data, wherein the comparison data shows accuracy of measurement of the at least one power parameter by the legacy instrumentation.

2. The system of claim 1, wherein the line device further comprises:

a sensor interfacing with the power line and producing one or more data indicative of the at least one power parameter;

a processor coupled with the sensor and producing the indication of the at least one power parameter from the one or more data; and

communication circuitry coupled with the processor to communicate the indication of the at least one power parameter to the microprocessor based device, wherein, prior to the line device being coupled to the power line, the legacy instrumentation has already been installed and has been monitoring the power line such that the second indication can be erroneous due to age of the legacy instrumentation, deterioration of the legacy instrumentation, or operating range of the legacy instrumentation.

3. The system of claim 2, wherein the sensor further comprises a split core enabling the sensor to be clamped along a longitudinal axis of the power line.

4. The system of claim 2, wherein the communication circuitry further comprises a wireless communication circuit.

5. The system of claim 1, wherein the system further comprises memory, coupled to the processor, that stores a plurality of the one or more data;

and wherein the processor communicates the plurality of the at least one data indicative of the at least one power parameter to the microprocessor based device.

6. The system of claim 1, wherein the line device is powered by at least one battery.

7. The system of claim 1, wherein the line device is powered by the electric power line.

8. The system of claim 1, wherein one of the at least one power parameter is current flow in the electric power line.

9. The system of claim 1, wherein the line device further comprises time circuitry coupled to the line device, the time circuitry receiving time data from a time source, and wherein the line device associates the time data with the at least one power parameter.

10. The system of claim 1, wherein the line device further comprises position circuitry coupled to the line device, the position circuitry receiving position data, and wherein the line device associates the position data with the at least one power parameter.

11. The system of claim 1, wherein the line device monitors the power parameter over a normal range of operation of the legacy instrumentation and stores at least the first indication within memory on the line device.

12. An apparatus comprising:

a line device coupled with a power line and producing at least one representation of a power parameter of the power line;

a processor coupled to the line device and receiving the at least one representation and producing at least one modified representation thereof;

communication circuitry coupled to the processor and communicating the at least one modified representation to a microprocessor based device;

wherein the microprocessor based device tests the accuracy of legacy instrumentation coupled to the power line by comparing the at least one modified representation to a measurement of at least one power parameter of the power line taken by the legacy instrumentation.

13. The apparatus of claim 12, wherein the line device monitors the power parameter over a normal range of operation of the legacy instrumentation and stores the at least one representation within memory on the line device.

14. The apparatus of claim 12, further comprising time circuitry coupled to the processor, the time circuitry receiving time data from a time source, wherein the processor associates the time data with the at least one modified representation.

15. The apparatus of claim 12, further comprising position circuitry coupled to the processor, the position circuitry receiving position data, wherein the processor associates the position data with the at least one modified representation.

16. The apparatus of claim 12, wherein the line device is powered by at least one battery.

17. The apparatus of claim 12, wherein the line device is powered by the electric power line.

18. The apparatus of claim 12, the line device further comprising a split core sensor enabling the line device to be clamped along a longitudinal axis of the power line.

19. The apparatus of claim 12, wherein the communication circuitry further comprises a wireless communication circuit.

20. A method comprising the steps of:

monitoring, by a line device, at least one power parameter of an electric power line and producing at least one representation thereof;

communicating the at least one representation to a microprocessor based device; and

comparing the representation with a measurement of the at least one power parameter of the power line produced by legacy instrumentation coupled to the power line.

21. The method of claim 20, further comprising the step of uncoupling the line device from the power line after monitoring the at least one parameter over a normal range of operation of the legacy instrumentation.

22. The method of claim 20, wherein the step of monitoring further comprises:

producing at least one sample indicative of at least one of a voltage and a current in the power line; and

associating a timestamp with each sample.

23. The method of claim 20, wherein the step of communicating comprises utilizing at least one wireless communication circuit.

24. The method of claim 20, further comprising:

coupling the line device to the power line after the legacy instrumentation has already been installed and has been monitoring the power line such that the measurement can be erroneous due to age of the legacy instrumentation, deterioration of the legacy instrumentation, or operating range of the legacy instrumentation;

responsive to the comparing producing a difference between the representation and the measurement, correcting the measurement to produce a corrected measurement; and

responsive to the correcting, decoupling the line device from the power line while the legacy instrumentation remains coupled to the power line after the comparing.