Watt-hour meter with communication on diagnostic error detection

• US 6,043,642 A
• Filed: 08/01/1997
• Issued: 03/28/2000
• Est. Priority Date: 08/01/1996
• Status: Expired due to Term

• Current Assignee: Landis+Gyr AG (Landis+Gyr Group AG)
• Original Assignee: Siemens Power Transmission & Distribution Incorporated (Siemens AG)
• Inventors: Anderson, Michael K., Watson, William James, Martin, Warren T., Bond, Randal K., Grisham, Gregory A.
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): Hollington, Jermele M.
• Application Number:
  US08/905,096
• Time in Patent Office: 970 Days
• Field of Search: 324/142, 324/103 R, 324/116, 324/104
• US Class Current: 324/142
• CPC Class Codes: G01R 22/00 Arrangements for measuring time integral of electric power or current, e.g. electricity meters
• CPC Class Codes: G01R 35/04 of instruments for measuring time integral of power or current

Abstract

An electrical utility meter includes measurement error diagnostic capabilities with intelligent communication capabilities. In an exemplary embodiment, the present invention includes an electrical utility meter for measuring energy consumption by a load. The electrical utility meter includes, sensor circuitry, a conversion circuit, a communication circuit, and a controller. The sensor circuitry connects to a meter socket. The meter socket connects to a plurality of power lines that, in turn, connect the load to a source of electrical power. The source of electrical power provides power to the load in a plurality of phases. The sensor circuitry generates voltage and current measurement signals representative of the voltage and current waveforms on the plurality of power lines. The conversion circuit is connected to the sensor circuitry and generates a power consumption measurement, as well as measured phase angle data for the plurality of phases, all of which are generated based on the voltage and current measurement signals. The communication circuit is connected to a remotely located control device. The controller is connected to the memory, the communication circuit, and the conversion circuit. The controller is operable to receive measured phase angle data for the plurality of phases, periodically perform a plurality of diagnostic tests using the measured phase angle data to determine whether a measurement error is present, and provide an alert signal to the communication circuit if a measurement error is present. The communication circuit, upon receiving the alert signal, is operable to obtain information identifying the measurement error and transmit an error signal containing information identifying the measurement error to remotely located control device.

Claims

1. An electrical utility meter operably connected to a plurality of power lines through a meter socket, the plurality of power lines providing polyphase power to a load, the electrical utility meter operable to measure electrical energy consumption, the electrical utility meter comprising:

a) sensor circuitry for connection to the meter socket, said sensor circuitry operable to generate voltage and current measurement signals representative of voltage and current waveforms on the plurality of power lines;

b) a conversion circuit for generating a power consumption measurement and for generating measured phase angle data for the plurality of power lines, said generation of the power consumption measurement and measured phase angle data based on the voltage and current measurement signals;

c) a memory;

d) a communication circuit connected to a remotely located control device;

e) a controller operably connected to the memory, the communication circuit, and the conversion circuit, the controller operable to

receive the measured phase angle data from the conversion circuit,

periodically perform a plurality of diagnostic tests using the measured phase angle data to determine whether the measurement error is present,

provide an alert signal to the communication circuit if a measurement error is present,

and wherein said communication circuit is operable to, upon receiving the alert signal, obtain information identifying the measurement error and transmit an error signal containing information identifying the measurement error to the remotely located control device.

2. The electrical utility meter of claim 1 wherein said controller is further operable to identify the measurement error and store information identifying the measurement error in the memory, and wherein said communication circuit is further operable to obtain information identifying the measurement error from the memory.

3. The electrical utility meter of claim 1 wherein said communication device is operable to, after obtaining information identifying the measurement error,

determine whether to transmit the information identifying the measurement error based on the information identifying the measurement error and one or more predefined parameters, and

transmit the error signal if the communication circuit determines that the information identifying the measurement error is to be transmitted.

4. The electrical utility meter of claim 1 wherein said communication circuit further comprises a processor connected to said controller, said processor operable to control the operations of the communication circuit.

5. The electrical utility meter of claim 4 wherein the communication circuit further comprises a modem operably connected to receive the information identifying the measurement error, the modem operable to transmit the error signal identifying the measurement error to the remotely located control device using a telephone line.

6. An arrangement for use in an electrical utility meter operably connected to a plurality of power lines through a meter socket, the plurality of power lines providing power to a load, the meter operable to measure electrical energy consumption, the arrangement comprising:

a) a source of measured data comprising at least one of measured phase angle data corresponding to the plurality of power lines and measured magnitude data corresponding to the plurality of power lines;

b) a communication circuit connected to a remotely located control device;

c) a controller operably connected to the communication circuit and the source of measured data, the controller operable to

receive measured data corresponding to the plurality of power lines,

periodically perform a plurality of diagnostic tests using the measured data to determine whether a measurement error is present, and

cause the communication circuit to transmit an error signal containing information identifying the measurement error to the remotely located control device if the measurement error is present.

7. The arrangement of claim 6 wherein the controller is further operably to cause the communication circuit to transmit the error signal by providing an alert signal to the communication circuit if the measurement error is present, and wherein the communication circuit, upon receiving the alert signal, is operable to obtain information identifying the measurement error and transmit the error signal identifying the measurement error to the remotely located control device.

8. The arrangement of claim 6 further comprising a memory connected to the controller, said memory containing nominal data comprising at least one of nominal phase angle data corresponding to the plurality of power lines and nominal magnitude data corresponding to the plurality of power lines, and wherein said controller is further operable to retrieve at least a portion of the nominal data and periodically perform the plurality of diagnostic tests using the measured data and the retrieved portion of nominal data to determine whether the measurement error is present.

9. The arrangement of claim 6 wherein the source of measured data includes a source of measured phase angle data corresponding to the plurality of power lines, and wherein the controller is further operable to receive the measured phase angle data and periodically perform the plurality of diagnostic tests using the measured phase angle data.

10. The arrangement of claim 9 further comprising a memory connected to the controller, said memory containing nominal phase angle data corresponding to the plurality of power lines, and wherein said controller is further operable to retrieve at least a portion of the nominal phase angle data and periodically perform the plurality of diagnostic tests using the measured phase angle data and the retrieved portion of nominal phase angle data to determine whether the measurement error is present.

11. The arrangement of claim 9 further comprising a source of measured magnitude data corresponding to the plurality of power lines, and wherein the controller is further operable to receive the measured magnitude data and periodically perform the plurality of diagnostic tests using the measured phase angle data and the measured magnitude data to determine whether the measurement error is present.

12. The arrangement of claim 11 further comprising a memory connected to the controller, said memory containing nominal phase angle and magnitude data corresponding to the plurality of power lines, and wherein said controller is further operable to retrieve at least a portion of the nominal phase angle and magnitude data and periodically perform the plurality of diagnostic tests using the measured phase angle data, the measured magnitude data, and the retrieved portion of nominal phase angle and magnitude data to determine whether the measurement error is present.

13. The arrangement of claim 6 wherein the source of measured data includes a source of measured voltage phase angle data corresponding to the plurality of power lines and measured current phase angle data corresponding to the plurality of power lines, and wherein the controller is further operable to receive the measured voltage phase angle data and the measured current phase angle data and periodically perform the plurality of diagnostic tests using the measured voltage phase angle data and the measured current phase angle data.

14. The arrangement of claim 13 further comprising a memory connected to the controller, said memory containing nominal voltage and current phase angle data corresponding to the plurality of power lines, and wherein said controller is further operable to retrieve at least a portion of the nominal voltage and current phase angle data and periodically perform the plurality of diagnostic tests using the measured voltage phase angle data, the measured current phase angle data, and the retrieved portion of nominal voltage and current phase angle data to determine whether the measurement error is present.

15. The arrangement of claim 6 wherein the source of measured data includes a source of measured magnitude data corresponding to the plurality of power lines, and wherein the controller is further operable to receive the measured magnitude data and periodically perform the plurality of diagnostic tests using the measured magnitude data.

16. The arrangement of claim 15 further comprising a memory connected to the controller, said memory containing nominal magnitude data corresponding to the plurality of power lines, and wherein said controller is further operable to retrieve at least a portion of the nominal magnitude data and periodically perform the plurality of diagnostic tests using the measured magnitude data and the retrieved portion of nominal magnitude data to determine whether the measurement error is present.

17. The arrangement of claim 6 wherein said communication circuit further comprises a processor connected to said controller, said processor operable to control the operations of the communication circuit.

18. The arrangement of claim 17 wherein the controller further causes the communication circuit to transmit the error signal by providing an alert signal to the processor if the measurement error is present, and wherein the processor is operable to, upon receiving the alert signal, obtain information identifying the measurement error and transmit the error signal identifying the measurement error to the remotely located control device.

19. The arrangement of claim 17 wherein the communication circuit further comprises a modem connected to receive the information identifying the measurement error and is operable to transmit the error signal identifying the measurement error to the remotely located control device using a telephone line.

20. The arrangement of claim 17 wherein the processor is further operable to:

obtain information identifying the measurement error;

determine whether to transmit the information identifying the measurement error based on the one or more predefined parameters and the information identifying the measurement error; and

cause the communication circuit to transmit the error signal if it is determined that the information identifying the measurement error is to be transmitted.

21. The arrangement of claim 18 wherein the processor includes an idle state and an active state and wherein said processor changes from the idle state to the active state upon reception of the alert signal.

22. A method of performing diagnostics in an electrical utility meter connected to a plurality of power lines through a meter socket, the electrical utility meter comprising a communication circuit, a controller, and a source of measured data comprising at least one of measured phase angle data corresponding to the plurality of power lines and measured magnitude data corresponding to the plurality of power lines, the method comprising:

a) providing the measured data to the controller;

b) using the controller to periodically perform a plurality of diagnostic tests using the measured data to determine whether a measurement error is present; and

c) using the communication circuit to transmit an error signal containing information identifying the measurement error to a remotely located control device if the measurement error is present.

23. The method of claim 22 further comprising, after step b), the step of providing an alert signal to the communication circuit if the measurement error is present, and wherein step c) further comprises using the communication circuit, upon receiving the alert signal, to obtain information identifying the measurement error and transmit the measurement error to the remotely located control device.

24. The method of claim 22 wherein step b) further comprises periodically performing diagnostic tests using the measured data and nominal data retrieved from a memory.

25. The method of claim 22 wherein step a) further comprises providing the measured phase angle data, and step b) further comprises using the controller to periodically perform plurality of diagnostic tests using the measured phase angle data to determined whether the measurement error is present.

26. The method of claim 25 wherein step b) further comprises periodically performing diagnostic tests using the measured phase angle data and nominal phase angle data retrieved from a memory.

27. The method of claim 22 wherein step a) further comprises providing measured voltage phase angle data and measured current phase angle data to the controller and step b) further comprises using the controller to periodically perform the plurality of diagnostic tests using the measured voltage phase angle date and the measured current phase angle data to determine whether the measurement error is present.

28. The method of claim 27 wherein step b) further comprises periodically performing diagnostic tests using the measured voltage phase angle data, the measured current phase angle data, and nominal phase angle data retrieved from a memory.

29. The method of claim 22 wherein step a) further comprises providing measured magnitude data, and step b) further comprises using the controller to periodically perform the plurality of diagnostic tests using the measured magnitude data to determine whether the measurement error is present.

30. The method of claim 29 wherein step b) further comprises periodically performing diagnostic tests using the measured magnitude data and nominal magnitude data retrieved from a memory.