SYSTEM AND METHOD FOR MONITORING CHARACTERISTICS OF AN ELECTRICAL DEVICE

• US 20150130480A1
• Filed: 11/08/2013
• Published: 05/14/2015
• Est. Priority Date: 11/08/2013
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: General Electric Company
• Inventors: Berkcan, Ertugrul, Lee, Yongjae, Hasan, SM Shajedul, Wik, Steven William
• Granted Patent: US 9,479,848 B2
• Time in Patent Office: Days
• US Class Current: 324/633
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A remote monitoring system is presented. The system includes a sensor unit disposed in the electrical device, and configured to obtain measurement characteristics in response to a measurand of the electrical device, obtain reference characteristics insensitive to the measurand of the electrical device, and communicate the measurement characteristics and the reference characteristics using time varying electromagnetic fields. Further, the system includes a reader unit to establish a far-field communication with the sensor unit in the presence of at least one metallic interferer in the electrical device, wherein the reader unit is configured to receive the time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics in response to a radio frequency signal transmitted to the sensor unit, and determine the measurand of the electrical device based on at least one property of the received time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics.

Claims

1. A remote monitoring system for an electrical device, comprising:

a sensor unit disposed in the electrical device, and configured to

obtain measurement characteristics in response to a measurand of the electrical device,

obtain reference characteristics insensitive to the measurand of the electrical device, and

communicate the measurement characteristics and the reference characteristics using time varying electromagnetic fields; and

a reader unit to establish a far-field communication with the sensor unit in the presence of at least one metallic interferer in the electrical device, wherein the reader unit is configured to

receive the time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics in response to at least one radio frequency signal transmitted to the sensor unit, and

determine the measurand of the electrical device based on at least one property of the received time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics.

2. The remote monitoring system of claim 1, wherein the sensor unit comprises at least one sensor tag disposed at a sensing position on a metallic platform of the electrical device.

3. The remote monitoring system of claim 2, wherein the at least one sensor tag is configured to obtain the measurement characteristics in the presence of the at least one metallic interferer in the electrical device.

4. The remote monitoring system of claim 2, wherein the measurement characteristics comprise a change in at least one parameter of the sensor tag in response to the measurand of the electrical device.

5. The remote monitoring system of claim 4, wherein the parameter of the sensor tag comprises at least one of impedance, dielectric constant, resistance, capacitance, inductance, geometrical parameters, and combinations thereof.

6. The remote monitoring system of claim 2, wherein the at least one sensor tag is disposed at a distance ranging from about 10 cm to about 125 cm from the reader unit.

7. The remote monitoring system of claim 2, wherein the sensor unit comprises at least one reference tag disposed at a reference position in the electrical device, wherein the reference position is at a pre-determined distance from the sensing position in the electrical device.

8. The remote monitoring system of claim 7, wherein the reference characteristics comprise at least one parameter of the at least one reference tag, wherein the at least one parameter comprises impedance, impedance change, a geometrical parameter, a coupling parameter, a dielectric constant, gain, resonant frequency, resonant frequency shift, and combinations thereof.

9. The remote monitoring system of claim 1, wherein the sensor unit communicates the measurement characteristics using the time varying electromagnetic fields when the at least one RF signal comprising a first RF signal is received from the reader unit.

10. The remote monitoring system of claim 9, wherein the sensor unit communicates the reference characteristics using the time varying electromagnetic fields when the at least one RF signal comprising a second RF signal is received from the reader unit.

11. The remote monitoring system of claim 1, wherein the property of the received time varying electromagnetic fields comprises at least one of return signal strength, resonant frequency, resonant frequency shift, polarization, reflection coefficient, backscatter ratio, radar cross section, absorption, and combinations thereof.

12. The remote monitoring system of claim 1, wherein the at least one property of the received time varying electromagnetic fields comprises at least one of delay, phase shift, timing, time characteristics, and combinations thereof.

13. A sensor device comprising:

a sensing sub-unit configured to obtain at least one of

measurement characteristics in response to a measurand of an electrical device at one or more sensing positions, and

reference characteristics insensitive to the measurand of the electrical device;

a matching element coupled to the sensing sub-unit and configured to vary characteristics of the matching element corresponding to one of the measurement characteristics and the reference characteristics; and

an electromagnetic field responsive element coupled to the matching element and configured to communicate one of the measurement characteristics and the reference characteristics using time varying electromagnetic fields corresponding to the characteristics of the matching element.

14. The sensor device of claim 13, wherein the sensing sub-unit comprises a sensing element configured to obtain the measurement characteristics as a change in at least one parameter of the sensing element.

15. The sensor device of claim 14, wherein the at least one parameter of the sensing element comprises at least one of an impedance, dielectric constant, resistance, capacitance, inductance, geometrical parameters, and combinations thereof.

16. The sensor device of claim 14, wherein the sensing sub-unit comprises a reference element configured to obtain the reference characteristics based on at least one parameter of the reference element.

17. The sensor device of claim 16, wherein the at least one parameter of the reference element comprises at least one of impedance, impedance change, a geometrical parameter, a coupling parameter, a dielectric constant, gain, resonant frequency, and resonant frequency shift, and combinations thereof.

18. The sensor device of claim 16, wherein the sensing sub-unit comprises a control switch coupled to the matching element, and wherein the control switch is configured to:

electrically couple the sensing element to the matching element when a first RF signal is received from the reader unit; and

electrically couple the reference element to the matching element when a second RF signal is received from the reader unit.

19. The sensor device of claim 18, wherein the control switch is configured to couple the matching element to one of the sensing element and the reference element when a pre-authorized signal is received from the reader unit.

20. The sensor device of claim 13, wherein the characteristics of the matching element comprises at least impedance of the matching element.

21. The sensor device of claim 13, wherein the electromagnetic field responsive element comprises at least one of a rectangular micro-strip antenna, a patch antenna, a monopole antenna, a planar inverted-F antenna, a quarter-wavelength patch, and a spiral antenna.

22. A reader device comprising:

an antenna to establish far-field communication with a sensor device disposed in an electrical device, and configured to receive time varying electromagnetic fields associated with measurement characteristics and the reference characteristics in response to a radio frequency signal transmitted to the sensor device; and

a reader-processor coupled to the antenna and configured to determine a measurand of the electrical device based on at least one property of the received time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics.

23. The reader device of claim 22, wherein the reader-processor is configured to determine the measurand of the electrical device independent of at least one error source in the electrical device.

24. The reader device of claim 23, wherein the error source comprises at least one of power level shifts, reader power shifts, ambient temperature, ambient moisture, and changes to conditions external to the operation of the electrical device.

25. A method for monitoring an electrical device, comprising:

obtaining, by a sensor unit, measurement characteristics in response to a measurand of the electrical device;

obtaining, by the sensor unit, reference characteristics insensitive to the measurand of the electrical device;

communicating, by the sensor unit, the measurement characteristics and the reference characteristics using time varying electromagnetic fields to a reader unit;

receiving, by the reader unit, the time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics in response to a radio frequency signal transmitted to the sensor unit; and

determining, by the reader unit, the measurand of the electrical device based on at least one property of the received time varying electromagnetic fields associated with the measurement characteristics and the reference characteristics.

26. The method of claim 25, wherein communicating the measurement characteristics and the reference characteristics comprises sending the time varying electromagnetic fields in the presence of at least one metallic interferer in the electrical device.