Signal feedback circuit in power-line-communication systems

• US 9,369,180 B1
• Filed: 09/26/2013
• Issued: 06/14/2016
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: Landis+Gyr Inc. (Landis+Gyr Group AG)
• Original Assignee: Landis+Gyr Inc. (Landis+Gyr Group AG)
• Inventors: Bonicatto, Damian
• Primary Examiner(s): Deberadinis, Robert
• Application Number:
  US14/038,303
• Time in Patent Office: 992 Days
• Field of Search: 307/3
• US Class Current: 1/1
• CPC Class Codes: H04B 17/00 Monitoring; Testing of line transmission systems H04B3/46; arrangements for monitoring or testing transmission systems employing electromagnetic waves other than radio waves H04B10/07
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT

Abstract

An apparatus is provided for data communication over power lines in a PLC system. The apparatus includes a data-coupling circuit configured to provide data to the power lines for transmission. The data-coupling circuit includes a DC-isolation circuit configured to isolate circuitry of the data-coupling circuit from the power lines. The apparatus also includes a feedback circuit connected to the DC-isolation circuit. The feedback circuit has a power-tap circuit on an endpoint side of the feedback circuit. The power-tap circuit is configured to provide a feedback signal indicative of an estimate of an amount of power, current, and/or voltage provided from the data-coupling circuit through the DC-isolation circuit and to the power lines. Based on the feedback the signal, the strength of a transmitted may be adjusted (e.g., to maintain constant signal strength).

Claims

1. A power-line-communication (PLC) apparatus for data communication over power lines in a power-line communication system between a PLC collector circuit and its power-line-coupled endpoint circuits that measure power consumption at remotely-located facilities, the apparatus comprising:

a data-coupling circuit configured and arranged to communicatively couple data to the power lines for transmission to the PLC collector circuit, the data-coupling circuit including a DC-isolation circuit configured and arranged to isolate circuitry in the data-coupling circuit relative to the power lines; and

a feedback circuit connected to the DC-isolation circuit including a power-tap circuit, on an isolated circuitry side of the DC-isolation circuit, the power-tap circuit configured and arranged to provide a feedback signal indicative of an estimate of at least one of power, current and voltage being coupled from the data-coupling circuit through the DC-isolation circuit and to the power lines.

2. The power-line-communication (PLC) apparatus of claim 1, wherein the power-tap circuit includes a shunt-resistive circuit, and wherein the DC-isolation circuit is a power transformer having a primary side and a secondary side, wherein the isolated circuitry side corresponds to the primary side.

3. The power-line-communication (PLC) apparatus of claim 2, wherein the feedback signal is provided as first and second signals respectively corresponding to current and voltage, and further including signal-processing circuitry configured and arranged to convert at least one of the first signal and the second signal from an analog signal to a digital signal, and further including an adjust circuit configured and arranged to cause a gain adjustment for a signal being communicatively coupled to the power lines by the data-coupling circuit, in response to the feedback circuit.

4. The power-line-communication (PLC) apparatus of claim 1, wherein the DC-isolation circuit includes a power transformer having a primary side and a secondary side, wherein the isolated circuitry side corresponds to the primary side, wherein the feedback signal is provided as at least one of a current signal and a voltage signal, and further including a signal-processor circuit communicatively-connected to the feedback circuit and configured and arranged to assess at least one of the current signal and the voltage signal.

5. The power-line-communication (PLC) apparatus of claim 1, further including a signal-processor circuit communicatively-connected to the feedback circuit and configured and arranged to assess from the feedback signal a current signal and a voltage signal, and wherein the signal-processor circuit is further configured and arranged to indicate, in response to an assessment thereof, whether a constant voltage, relative to a threshold, is being applied to the isolated circuitry side.

6. The power-line-communication (PLC) apparatus of claim 1, wherein the data-coupling circuit includes a variable-gain circuit, and further including a signal-processor circuit communicatively-connected to the feedback circuit and configured and arranged to assess at least one of a current signal and a voltage signal, and wherein the signal-processor circuit is further configured and arranged to cause a gain adjustment of the variable-gain circuit, in response to an assessment of at least one of the current signal and the voltage signal.

7. The power-line-communication (PLC) apparatus of claim 1, wherein the data communication over power lines between a PLC collector circuit and its power-line-coupled endpoint circuits is G3-PLC compliant.

8. The power-line-communication (PLC) apparatus of claim 1, wherein the data communication over power lines between a PLC collector circuit and its power-line-coupled endpoint circuits is G3-PLC compliant, and wherein the endpoint circuits are power-meter circuits configured and arranged to provide power-meter reports by transmitting data symbols over a power line using a respective one of a plurality of data communication channels.

9. The power-line-communication (PLC) apparatus of claim 8, wherein the data-coupling circuit includes a variable-gain circuit, and further including a signal-processor circuit communicatively-connected to the feedback circuit and configured and arranged to assess the feedback signal, and wherein the signal-processor circuit is further configured and arranged to cause the variable-gain circuit to adjust or set an amplitude of the data coupled to the power lines, in response to an assessment of the feedback signal.

10. The power-line-communication (PLC) apparatus of claim 1, wherein

the data communication over power lines between a PLC collector and its power-line-coupled endpoint circuits is G3-PLC compliant and the data communication is affected by variances in power-line impedance,

the endpoint circuits are power-meter circuits configured and arranged to provide power-meter reports by transmitting data symbols over a power line using one or more Orthogonal Frequency Division Multiplexing (OFDM) data communication channels, and

the data-coupling circuit includes a variable-gain circuit, and further including a signal-processor circuit communicatively-connected to the feedback circuit and configured and arranged to assess the feedback signal, and wherein the signal-processor circuit is further configured and arranged to cause a gain adjustment of or setting to the variable-gain circuit, in response to an assessment of the feedback signal.

11. The power-line-communication (PLC) apparatus of claim 10, wherein the data communication over power lines between a PLC collector circuit and its power-line-coupled endpoint circuits is G3-PLC compliant and the data communication is effected by signals, in the form of data symbols, transmitted over designated ones of the plurality of data channels.

12. The power-line-communication (PLC) apparatus of claim 1, further including the PLC collector circuit and a plurality of the power-line-coupled endpoint circuits.

13. A system comprising:

a power-line-communication (PLC) collector circuit;

one or more endpoint circuits configured and arranged to transmit data symbols over a plurality of data channels by data communication over power lines connected between the PLC collector circuit and said one or more endpoint circuits; and

for each of the one or more endpoint circuits, a respective signal-processing circuit communicatively connected to or forming part of said one or more endpoint circuits, the signal-processing circuit including

a data-coupling circuit configured and arranged to provide a data signal from the endpoint to the power lines for transmission to the PLC collector circuit, the data-coupling circuit including a DC-isolation circuit configured and arranged to isolate circuitry of the data-coupling circuit relative to the power lines;

a feedback circuit connected to the DC-isolation circuit including a power-tap circuit, on the isolated circuitry side thereof, configured and arranged to characterize or estimate a power parameter applied to the power lines; and

the feedback circuit including a current-feedback or voltage-feedback circuit configured and arranged to provide a feedback signal that estimates current being coupled from the data-coupling circuit to the power lines.

14. The system of claim 13, wherein the feedback signal is provided as first and second signals respectively corresponding to current and voltage, the data-coupling circuit includes a variable-gain circuit, and further including a signal-processor circuit communicatively-connected to the feedback circuit and configured and arranged to assess at least one of the first signal and the second signal, and wherein the signal-processor circuit is further configured and arranged to cause a gain adjustment of or setting to the variable-gain circuit, in response to and based on an assessment of at least one of the first signal and the second signal.

15. The system of claim 13, wherein said one or more endpoint circuits includes a residential power meter.

16. A method for power-line-communication (PLC) of data over power lines between a PLC collector circuit and its power-line-coupled endpoint circuits that measure power consumption at remotely-located facilities, the method comprising:

providing a data-sending circuit including a DC-isolation data-coupling circuit configured to isolate circuitry of data-coupling circuitry relative to the power lines and including a feedback circuit having a current-feedback circuit or a voltage-feedback circuit configured for tapping or shunting power; and

using the current-feedback circuit and the voltage-feedback circuit to estimate or indicate at least one of an amount of current being coupled from the data-coupling circuit through the DC-isolation data-coupling circuit and to the power lines, and an amount of voltage applied from the data-coupling circuit through the DC-isolation data-coupling circuit and to the power lines.

17. The method of claim 16, further including adjusting an amplification setting or setting a gain for coupling data to the power lines, in response to and based on an assessment of the estimation or indication.

18. The method of claim 16, wherein the power-line-communication (PLC) of data over the power lines is G3-PLC compliant and the PLC is affected by variances in power-line impedance, and further including adjusting an amplification setting in response to and based on an assessment of the estimation or indication.

19. The method of claim 16, further including conditioning a feedback signal from the feedback circuit using a low-pass filter.

20. The method of claim 16, further including conditioning a feedback signal from the feedback circuit using an anti-aliasing filter.