Supervision of input signal channels

• US 9,843,335 B2
• Filed: 12/27/2016
• Issued: 12/12/2017
• Est. Priority Date: 12/29/2015
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Schweitzer, III, Edmund O., Skendzic, Veselin, Windley, Tracey G., Kasztenny, Bogdan Z.
• Primary Examiner(s): NGUYEN, LINH V
• Application Number:
  US15/391,521
• Publication Number:
  US 20170187385A1
• Time in Patent Office: 350 Days
• Field of Search: 341111-117, 341141, 702 60, 702 67, 702 71, 702 75, 702 70, 702 79, 324601, 324 6677, 324 7679, 324 7682
• CPC Class Codes: G01R 19/2509 Details concerning sampling, digitizing or waveform capturing
• CPC Class Codes: H03M 1/0607 Offset or drift compensation removal of offset already present on the analogue input signal H03M1/1295
• CPC Class Codes: H03M 1/1023 Offset correction H03M1/1019 takes precedence; removal of offset already present on the analogue input signal H03M1/1295
• CPC Class Codes: H03M 1/1076 Detection or location of converter hardware failure, e.g. power supply failure, open or short circuit
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: H03M 1/1205 Multiplexed conversion systems

Abstract

The present disclosure pertains to systems and methods for monitoring a plurality of analog-to-digital converters. In one embodiment, a plurality of input channels may each be in communication with a different phase of a three-phase electric power delivery system. The input channels may be configured to receive analog signals from the different phases. A composite signal subsystem may be configured to generate a composite signal based on the plurality of input channels. An analog-to-digital converter subsystem may be configured to produce a digitized representation of each of the plurality of input channels and a digitized representation of the composite signal. An analog-to-digital converter monitor subsystem may identify an error in the analog-to-digital conversion based on the digitized representation of the composite signal and the digitized representations of the plurality of input channels.

Claims

1. A system configured to monitor a plurality of analog-to-digital converters, comprising:

a plurality of input channels, each in communication with a different phase of a three-phase electric power delivery system, and configured to receive a plurality of analog signals from the three phases;

a composite signal subsystem configured to generate a composite signal based on the plurality of input channels;

an analog-to-digital converter subsystem in communication with the plurality of input channels and the composite signal subsystem, the analog-to-digital converter subsystem configured to produce a digitized representation of each of the plurality of input channels and a first digitized representation of the composite signal; and

a monitor subsystem in communication with the analog-to-digital converter subsystem and configured to identify at least one error in the digitized representation of at least one of the plurality of input channels produced by the analog-to-digital converter subsystem and based on the digitized representation of the composite signal and the digitized representations of the plurality of input channels.

2. The system of claim 1, wherein the composite signal comprises a time-varying combination of the plurality of analog signals.

3. The system of claim 1, wherein the composite signal comprises an arithmetic combination of the plurality of analog signals.

4. The system of claim 1, wherein the monitor subsystem is further configured to create a second digitized representation of the composite signal based on the digitized representations of the plurality of input channels, and to identify the error based on a comparison of the first digitized representation of the composite signal and the second digitized representation of the composite signal.

5. The system of claim 4, wherein the monitor subsystem is further configured to provide a representation of a magnitude of the at least one error.

6. The system of claim 5, wherein the magnitude of the at least one error is based on the first digitized representation of the composite signal and the second digitized representation of the composite signal.

7. The system of claim 5, wherein the representation of the magnitude comprises an output of a low pass filter.

8. The system of claim 1, wherein the monitor subsystem is further configured to identify the at least one error based on a combination of the digitized representation of the composite signal and the digitized representations of the plurality of input channels exceeding an immediate error threshold.

9. The system of claim 1, wherein the monitor subsystem is further configured to identify the at least one error based on a combination of the digitized representation of the composite signal and the digitized representations of the plurality of input channels exceeding a supervised error threshold a plurality of times in a specified window.

10. The system of claim 1, wherein the analog-to-digital converter subsystem comprises a plurality of analog-to-digital converters, and each of the plurality of input channels is associated with a corresponding analog-to-digital converter.

11. The system of claim 10, wherein the monitor subsystem is further configured to determine operation of each of the plurality of analog-to-digital converters associated with the plurality of input channels based on the composite signal.

12. The system of claim 1, wherein the monitor subsystem is further configured to invalidate the digitized representation based on the at least one error.

13. The system of claim 1, further comprising:

a monitored equipment interface configured to issue a control instruction to a piece of monitored equipment; and

a protection action subsystem configured to generate the control instruction based on the digitized representation of each of the plurality of input channels.

14. The system of claim 13, wherein the protection action subsystem is in communication with the monitor subsystem and is configured to suppress the control instruction based on the at least one error.

15. The system of claim 1, wherein the plurality of input channels are associated with one of a corresponding plurality of voltage signals and a corresponding plurality of current signals.

16. The system of claim 1, wherein the composite signal differs from each of the three phases.

23. The system of claim 1, wherein the analog-to-digital converter subsystem further comprises:

a plurality of analog-to-digital converters corresponding to the plurality of input channels and configured to produce a digitized representation of each of the plurality of input channels.

24. The system of claim 23, wherein the analog-to-digital converter subsystem further comprises:

an analog-to-digital converter configured to generate a digitized representation of the composite signal.

17. A system configured to monitor a plurality of analog-to-digital converters, comprising:

a plurality of input channels configured to receive a plurality of analog signals from the different phases;

a composite signal subsystem configured to generate a composite signal based on the plurality of input channels;

an analog-to-digital converter subsystem in communication with the plurality of input channels and the composite signal subsystem, the analog-to-digital converter subsystem configured to produce a digitized representation of each of the plurality of input channels and a first digitized representation of the composite signal; and

a monitor subsystem in communication with the analog-to-digital converter subsystem and configured to identify at least one error in the digitized representation of at least one of the plurality of input channels produced by the analog-to-digital converter subsystem and based on the digitized representation of the composite signal and the digitized representations of the plurality of input channels.

18. The system of claim 17, wherein the composite signal comprises a time-varying combination of the plurality of analog signals.

20. The system of claim 17, wherein the monitor subsystem is further configured to provide a representation of a magnitude of the at least one error.

21. The system of claim 17, wherein the monitor subsystem is further configured to identify the at least one error based on a combination of the digitized representation of the composite signal and the digitized representations of the plurality of input channels exceeding an immediate error threshold.

22. The system of claim 17, wherein the monitor subsystem is further configured to identify the at least one error based on a combination of the digitized representation of the composite signal and the digitized representations of the plurality of input channels exceeding a supervised error threshold a plurality of times in a specified window.

19. A system configured to monitor a plurality of analog-to-digital converters, comprising:

a plurality of input channels configured to receive a plurality of analog signals from the different phases;

a composite signal subsystem configured to generate a composite signal based on the plurality of input channels;

an analog-to-digital converter subsystem in communication with the plurality of input channels and the composite signal subsystem, the analog-to-digital converter subsystem configured to produce a digitized representation of each of the plurality of input channels and a first digitized representation of the composite signal; and

a monitor subsystem in communication with the analog-to-digital converter subsystem and configured to identify at least one error based on the digitized representation of the composite signal and the digitized representations of the plurality of input channels;

wherein the monitor subsystem is further configured to create a second digitized representation of the composite signal based on the digitized representations of the plurality of input channels, and to identify the error based on a comparison of the first digitized representation of the composite signal and the second digitized representation of the composite signal.