Claims
- 1. An apparatus for calculating the phase angle of at least one phasor relative to a selected base phasor in a multi-phase electrical system, the apparatus including:
- a microprocessor;
- memory storage means for storing accumulated digital values corresponding to the instantaneous voltage measured for the base phasor, X.sub.B ;
- memory storage means for storing accumulated digital values corresponding to the instantaneous value measured for another selected phasor X.sub.N ;
- logic for calculating, for a pre-defined period, the RMS values for X.sub.B and X.sub.N, denoted X.sub.B(RMS) and X.sub.N(RMS), respectively;
- logic for determining the product, P, of X.sub.B(RMS) and X.sub.N(RMS) ;
- logic for determining the average value, Q, of the product of the two sine waves corresponding to X.sub.B and X.sub.N ;
- logic for determining the average value, Y, of the product of the two sine waves corresponding to a shifted version of X.sub.B, denoted X.sub.B(-90), and X.sub.N ;
- logic for determining the phase angle .theta. equal to arccos (Q/P).
Parent Case Info
This application is a division of U.S. patent application Ser. No. 08/037,938, filed on Mar. 26, 1993, pending, entitled "SYSTEM CHECKING AND TROUBLESHOOTING PACKAGE FOR AN ELECTRICTRONIC METERING DEVICE".
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4612617 |
LaPlace, Jr. et al. |
Sep 1986 |
|
5212441 |
McEachern et al. |
May 1993 |
|
5302890 |
McEachern et al. |
Apr 1994 |
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5315235 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
37938 |
Mar 1993 |
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