Time-of-use and demand metering in conditions of power outage with a mobile node

• US 6,006,212 A
• Filed: 12/09/1997
• Issued: 12/21/1999
• Est. Priority Date: 09/17/1997
• Status: Expired due to Term

• Current Assignee: Itron, Inc.
• Original Assignee: Itron, Inc.
• Inventors: Myers, Gregory K., Schleich, Michael G.
• Primary Examiner(s): Cosimano, Edward R.
• Assistant Examiner(s): Dixon, Thomas A.
• Application Number:
  US08/987,677
• Time in Patent Office: 742 Days
• Field of Search: 705/412, 705/413, 705/417, 705/418, 705/400, 702/60, 702/61, 702/62, 702/64, 702/65, 340/870.02, 340/870.03, 340/870.07, 340/870.11, 324/114, 324/115, 324/116, 324/140 R, 324/142
• US Class Current: 705/412
• CPC Class Codes: G01D 4/006 Remote reading of utility meters to a non-fixed location, i.e. mobile location
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G01R 22/00 Arrangements for measuring time integral of electric power or current, e.g. electricity meters
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

An RF based communication system includes a transmitter for transmitting a signal. The transmitter is powered by an external power source and has a transmitter counter for generating a count. The count is linearly incremented over time. The transmitted signal includes the count at the time that the signal is transmitted. A receiver is communicatively coupled to the transmitter for receiving the signal transmitted by the transmitter. The receiver has a receiver counter, the receiver counter being asynchronous with respect to the transmitter counter.

Claims

1. An RF based communication system, comprising:

transmitter means for transmitting a signal, being powered by an external power source and having a transmitter counter for generating a count that is linearly incremented over time, the transmitted signal including the count at the time that the signal is transmitted; and

receiver means being communicatively coupled to the transmitter means for receiving the signal transmitted by the transmitter means, having a receiver counter, the receiver counter being asynchronous with respect to the transmitter counter.

2. The RF based communication system of claim 1 wherein the receiver means includes a microprocessor, the microprocessor calculating the slope of the incrementally increasing count of the transmitter counter.

3. The RF based communication system of claim 2 wherein the microprocessor calculates a predicted count for the transmitter counter at a selected count of the receiver counter.

4. The RF based communication system of claim 1 wherein the receiver means and the transmitter means are passively time synchronized by comparing the counts of the asynchronous receiver counter and the transmitter counter.

5. The RF based communication system of claim 3 wherein the microprocessor calculates the difference between the predicted count of the transmitter counter and the count of the transmitter counter, the difference providing an indication of the occurrence of a power outage in the external power source and the duration of said power outage.

6. A metering communication system for communicating data related to metered consumption of electrical energy to provide support for time-of-use and demand billing in the presence of at least one power outage event, the metering communication system being communicatively coupled to a sensor for sensing power consumption and for sensing power outage events, the sensor generating a sensor output signal having data related to at least the sensed power consumption and to power outage events, the metering communication system comprising:

a. an encoder device having;

means for communication with the sensor for receiving the sensor output signal therefrom; and

means for periodically generating an encoded RF signal for transmission by the encoder device, the signal having a power outage flag associated therewith, the flag being set responsive to the sensor output signal including data related to a power outage event; and

b. an interrogate/receiver device having;

decoder means being communicatively coupled to the encoder device for decoding the encoded RF signal received from the encoder device; and

data transfer means for transferring the decoded RF signal to a billing system.

7. The metering system of claim 6 wherein the encoded RF signal has a plurality of discrete components, each of said components being related to electrical power consumption during a selected interval of time, a power outage flag being associated with each discrete component.

8. The metering system of claim 7 wherein the encoder device is powered solely by the electrical power being metered.

9. The metering system of claim 7 wherein the encoder device includes encoder counter means for incrementally increasing a count as a function of time.

10. The metering system of claim 9 wherein the interrogate/receiver device includes receiver counter means for incrementally increasing a count as a function of time, the receiver counter means being asynchronous with respect to the encoder counter means.

11. The metering system of claim 10 wherein the receiver counter means counts at a rate substantially equal to a real time counter.

12. The metering system of claim 10 wherein the interrogate/receiver device flags the decoded RF signal received from the encoder device prior to transmission to a billing system for each interval in which the consumption of electrical energy is estimated.

13. The metering system of claim 10 wherein the interrogate/receiver device determines the difference between a predicted and an actual encoder counter means count to predict a total power outage duration.

14. The metering system of claim 13 wherein the interrogate/receiver device determines the difference between a predicted and an actual encoder counter means count to predict a total power outage duration of a plurality of power outages.

15. The metering system of claim 14 wherein the encoder device includes a microprocessor, the microprocessor having a buffer assigned in a non-volatile memory, a pointer in the microprocessor indicating a position in the buffer corresponding to a N-1 consumption value, the N-1 consumption value being a differentially encoded consumption value which occurred at a most recent consumption interval.

16. The metering system of claim 15 wherein the pointer is incremented to identify each newly received N-1 consumption value.

17. The metering system of claim 16 wherein the buffer has N-1 bins, each of said bins having a differential consumption value stored therein and being written to once every N-1 intervals.

18. The metering system of claim 17 wherein the most recently received differential consumption value displaces the oldest consumption value in the buffer, the pointer incrementing by one to indicate the most recently received differential consumption value at the time of displacement.

19. The metering system of claim 18 wherein the most recently arrived full consumption value and the buffer pointer are written to non-volatile memory at the time of a power outage.

20. A metering communication system for communicating data related to metered consumption of electrical energy to provide support for demand billing in the presence of at least one power outage event, the metering communication system being communicatively coupled to a sensor, the sensor for sensing power consumption and for sensing power outage events, the sensor generating a sensor output signal having data related to at least the sensed power consumption and to power outage events, the metering communication system comprising:

a. an encoder device having;

means for communication with the sensor for receiving the sensor output signal therefrom;

a microprocessor, the microprocessor having a buffer assigned in a non-volatile memory, a pointer in the microprocessor indicating a position in the buffer corresponding to a N-1 consumption value, the N-1 consumption value being a differentially encoded consumption value which occurred at a most recent consumption interval; and

means for periodically generating an encoded RF signal for transmission by the encoder device; and

b. an interrogate/receiver device having;

decoder means being communicatively coupled to the encoder device for decoding the encoded RF signal received from the encoder device; and

data transfer means for transferring the decoded RF signal to a billing system.

21. The metering system of claim 20 wherein the pointer is incremented to identify each newly received N-1 consumption value.

22. The metering system of claim 21 wherein the buffer has N-1 bins, each of said bins having a full consumption value stored therein and being written to once every N-1 intervals.

23. The metering system of claim 22 wherein the most recently received differential consumption value displaces the oldest consumption value in the buffer, the pointer incrementing by one to indicate the most recently received differential consumption value at the time of displacement.

24. The metering system of claim 23 wherein the most recently arrived full consumption value and the buffer pointer are written to non-volatile memory at the time of a power outage.

25. The metering system of claim 24 wherein the encoded RF signal has a power outage flag associated therewith, the flag being set responsive to the sensor output signal including data related to a power outage event.

26. A metering communication system for communicating data related to metered consumption of electrical energy to provide support for time-of-use billing in the presence of at least one power outage event, the metering communication system being communicatively coupled to a sensor for sensing power consumption and for sensing power outage events, the sensor generating a sensor output signal having data related to at least the sensed power consumption and to power outage events, the metering communication system comprising:

a. an encoder device having;

means for communication with the sensor for receiving the sensor output signal therefrom;

encoder counter means for incrementally increasing a count as a function of time; and

means for periodically generating an encoded RF signal for transmission by the encoder device, the encoded RF signal having the current count of the encoder counter means associated therewith; and

b. an interrogate/receiver device having;

decoder means being communicatively coupled to the encoder device for decoding the encoded RF signal received from the encoder device;

receiver counter means for incrementally increasing a count as a function of time, the receiver counter means being asynchronous with respect to the encoder counter means; and

data transfer means for transferring the decoded RF signal to a billing system.

27. A metering communication system as claimed in claim 26 the count of the encoder counter means related to the count of the receiver counter means providing passive synchronization of the encoder device and the interrogate/receiver device for time stamping data related to the sensed power consumption.

28. The metering system of claim 26 wherein the receiver counter means counts at a rate substantially equal to a real time counter.

29. The metering system of claim 26 wherein the interrogate/receiver device flags the decoded RF signal received from the encoder device prior to transmission to a billing system for each interval in which the consumption of electrical energy is estimated.

30. The metering system of claim 26 wherein the interrogate/receiver device determines the difference between a predicted and an actual encoder counter means count to predict a total power outage duration.

31. The metering system of claim 30 wherein the interrogate/receiver device determines the difference between a predicted and an actual encoder counter means count to predict a total power outage duration of a plurality of power outages.