System checking and troubleshooting package for an electronic metering device

• US 5,469,049 A
• Filed: 03/26/1993
• Issued: 11/21/1995
• Est. Priority Date: 03/26/1993
• Status: Expired due to Term

• Current Assignee: Itron, Inc.
• Original Assignee: Schlumberger Industries Incorporated (Schlumberger NV)
• Inventors: Hyder, Charles C., Schlarb, John M., Lowe, Coy S., Briese, Forrest W., Fouquet, Christophe J. A.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): BOWSER, BARRY
• Application Number:
  US08/037,938
• Time in Patent Office: 970 Days
• Field of Search: 324/142, 324/73, 324/140, 324/141, 324/107, 324/74, 324/46, 324/483, 324/481, 324/115, 324/102, 324/637, 324/657, 324/601, 324/86, 324/130, 324/76, 324/77
• US Class Current: 324/76.77
• 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: G01R 35/04 of instruments for measuring time integral of power or current

Abstract

An integral electronic meter system diagnostics package including a microprocessor, storage memory, logic for automatically and periodically performing a pre-select series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period.

Claims

1. In a solid state electronic meter including means for ascertaining current and voltage information from a multi-phase electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, one of said predefined multi-phase electrical system diagnostic tests being a polarity, cross-phase and energy flow check, and wherein said first logic includes logic for designating a base phasor, and determining the phase angle θ

for each of the phasors in said multi-phase electrical system relative to the base phasor; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

2. In a solid state electronic meter including means for ascertaining current and voltage information from a multi-phase electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, one of said predefined multi-phase electrical system diagnostic tests being a polarity, cross-phase and energy flow check, and wherein said first logic includes logic for calculating for each phase a voltage phasor, a current phasor, and a phase angle for each voltage phasor and each current phasor relative to a selected base phasor; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

3. In a solid state electronic meter including means for ascertaining current and voltage information from a multi-phase electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, said first logic including logic for calculating for each phase a voltage, a current, and a phase angle for each voltage and each current for each phase relative to a preselected base phasor; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

4. In a solid state electronic meter including means for ascertaining current and voltage information from a multi-phase electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, said first logic including logic for determining the phase angle of at least one phasor relative to a selected base phasor, including storing accumulated digital values corresponding to the instantaneous voltage measured for the base phasor, X_B, storing accumulated digital values corresponding to the instantaneous value measured for another selected phasor, X_N determining, for a predefined period, the RMS values for X_B and X_N, denoted X_B(RMS) and X_N(RMS) respectively, determining the product, P, of X_B(RMS) and X_N(RMS), determining the average value, Q, of the product of the two sine waves corresponding to X_B and X_N and determining the average value, Y, of the product of the two sine waves corresponding to a shifted version of X_B, denoted X_B(-90) ; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

5. The invention of claim 4 wherein the logic further includes logic for determining the magnitude of the phase angle of the one phasor relative to the selected base phasor, θ

, equal to arccos (Q/P).

6. The invention of claim 5 further including logic for determining if the phasor is lagging or leading the selected base phasor, including logic for determining θ

, equal to arcsine (Y/P).

7. In a solid state electronic meter including means for ascertaining current and voltage information from an electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, said preselected set of multi-phase electrical system diagnostic tests including a phase voltage deviation check, and wherein said first logic includes logic for periodically measuring the voltage for each phase in said electrical system and comparing it to a predefined voltage envelope; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

8. In a solid state electronic meter including means for ascertaining current and voltage information from an electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, said preselected set of multi-phase electrical system diagnostic tests including a current transformer check, and wherein said first logic includes logic for periodically measuring the instantaneous RMS current for each phase and comparing it to a predefined current value; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

9. In a solid state electronic meter including means for ascertaining current and voltage information from an electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom, said preselected set of multi-phase electrical system diagnostic tests including a per-phase power factor check, and wherein said first logic includes logic for periodically calculating the angle between the current phasor and the idealized voltage phasor, and comparing the angle to a predefined envelope; and

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period.

10. In a solid state electronic meter including means for ascertaining current and voltage information from an electrical system metered thereby, a meter self-checking and electrical system diagnostic device, said device including:

(a) a microprocessor;

(b) a storage memory;

(c) first logic for periodically performing a preselected set of diagnostic tests on said multi-phase electrical system and recording any errors detected therefrom;

(d) display means for displaying the error messages identifying any errors discovered in said multi-phase electrical system diagnostic tests performed during a predefined period; and

(e) display means for displaying a diagnostic toolbox in response to an activation signal, said diagnostic toolbox comprising a fixed selected set of display items including selected information developed from said multi-phase electrical system diagnostic tests.

11. The invention of claim 10 wherein the system continues to perform normal meter operations while the toolbox display is activated.