US5537333A
Expired / Lapsed
US
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Method of determining power measurements in an electrical energy meter
Assignee: Elster Solutions LLC
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Filing: 1995-06-07
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Granted: 1996-07-16
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Expires: 2015-06-07
Abstract
Abstract A method is described for metering electrical energy. The method includes sensing each phase of a circuit to generate analog voltage signals and analog current signals associated with each phase. The analog voltage signals and said analog current signals are converted into digital voltage signals and digital current signals, respectively, using time division multiplexing to provide three digital outputs. The digital outputs comprise at least one digital voltage signal and at least one digital current signal associated with the same phase. The digital outputs are processed to generate signals representative of real power, the magnitude of reactive power, and apparent power, wherein the signals representative of the magnitude of reactive power are generated from the signals representative of real power and the signals representative of apparent power.
Inventors
- 👤 Rodney C. Hemminger
- 👤 Mark L. Munday
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:37
CPC Classifications
G; G06; G06Q; G06Q30/00; G06Q30/04; G01; G01R; G01R21/00; G01R21/133; H; H02; H02J; H02J13/00; H02J13/13; H02J13/1317; Y; Y04; Y04S; Y04S50/00; Y04S50/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
125 words
A method of metering electrical energy comprising the steps of: sensing each phase of a circuit to generate analog voltage signals and analog current signals associated with each phase; converting said analog voltage signals and said analog current signals into digital voltage signals and digital current signals, respectively, using time division multiplexing to provide three digital outputs, each digital output comprising at least one digital voltage signal and at least one digital current signal associated with the same phase; and processing said digital outputs to generate signals representative of real power, the magnitude of reactive power, and apparent power, wherein said signals representative of the magnitude of reactive power are generated from said signals representative of real power and said signals representative of apparent power.
Claim 2
Independent Claim
125 words
A method of metering electrical energy comprising the steps of: sensing each phase of a circuit to generate analog voltage signals and analog current signals associated with each phase; converting said analog voltage signals and said analog current signals into digital voltage signals and digital current signals, respectively, using time division multiplexing to provide three digital outputs, each digital output comprising at least one digital voltage signal and at least one digital current signal associated with the same phase; and processing said digital outputs to generate signals representative of real power, the magnitude of reactive power, and apparent power, wherein said signals representative of the magnitude of reactive power are generated from said signals representative of real power and said signals representative of apparent power.
Claim 3
Dependent Claim
33 words
The method of claim 1, wherein said processing step comprises the step of: processing said digital voltage signals and said digital current signals to generate an RMS voltage and an RMS current, respectively.
Claim 4
Dependent Claim
93 words
The method of claim 2, wherein the meter is configured for a 2-element, 3-wire delta application such that said digital outputs are processed in accordance with the following formula: ##EQU1## where all V values represent voltages, all I values represent currents, and all K values represent calibration constants, wherein subscripts A, B, and C represent phases of the circuit, and sub-subscripts 0, 1, and 2 represent each of said three digital outputs, and wherein all RMS subscripts of V and I values indicate the value is the RMS voltage and RMS current, respectively.
Claim 5
Dependent Claim
94 words
The method of claim 2, wherein the meter is configured for a 3-element, 4-wire wye application such that said digital outputs are processed in accordance with the following formula: ##EQU2## where all V values represent voltages, all I values represent currents, and all K values represent calibration constants, wherein subscripts A, B, and C represent phases of the circuit, and sub-subscripts 0, 1, and 2 represent each of said three digital outputs, and wherein all RMS subscripts of V and I values indicate the value is the RMS voltage and the RMS current, respectively.
Claim 6
Dependent Claim
94 words
The method of claim 2, wherein the meter is configured for a 3-element, 4-wire delta application such that said digital outputs are processed in accordance with the following formula: ##EQU3## where all V values represent voltages, all I values represent currents, and all K values represent calibration constants, wherein subscripts A, B, and C represent phases of the circuit, and sub-subscripts 0, 1, and 2 represent each of said three digital outputs, and wherein all RMS subscripts of V and I values indicate the value is the RMS voltage and the RMS current, respectively.
Claim 7
Dependent Claim
94 words
The method of claim 2, wherein the meter is configured for a 21/2-element, 4-wire delta application such that said digital outputs are processed in accordance with the following formula: ##EQU4## where all V values represent voltages, all I values represent currents, and all K values represent calibration constants, wherein subscripts A, B, and C represent phases of the circuit, and sub-subscripts 0, 1, and 2 represent each of said three digital outputs, and wherein all RMS subscripts of V and I values indicate the value is the RMS voltage and the RMS current, respectively.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-07-16 | 2000-01-15 | 2000-07-16 | $2000.00 | Window Closed / Lapsed |
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