Harmonic-adjusted power factor meter
First Claim
1. An instrument for measuring electric power consumed by a consumer, comprising:
- a. first means for measuring watt consumption;
b. second means for measuring volt-ampere consumption coupled to the means for measuring watt consumption;
c. third means for calculating a frequency-domain power factor parameter comprising a function of a ratio of watt-hours to volt-ampere-hours coupled to receive a data signal from the first means and the second means; and
d. fourth means for adjusting the power factor parameter in a predetermined manner related to the non-fundamental currents and non-fundamental voltages.
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Accused Products
Abstract
An electric power measuring system wherein power factor measurements are adjusted to reflect the adverse economic effects of harmonic currents and voltages. Well-known techniques are used to acquire frequency spectra that represent the voltages and currents present at the measuring point. These spectra are weighted in such a way that non-fundamental currents are increased and non-fundamental voltages are decreased. The weighted spectra are used to calculate a harmonic-adjusted volt-ampere measurement, which is then accumulated to form a harmonic-adjusted volt-ampere-hour measurement. The weighting functions for voltage and current are selected to approximate the economic impact on the AC power generating, transmission, and distribution system of non-fundamental currents and voltages. The resulting harmonic-adjusted volt-ampere-hour measurement is used to calculate a harmonic-adjusted power factor measurement.
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Citations
5 Claims
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1. An instrument for measuring electric power consumed by a consumer, comprising:
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a. first means for measuring watt consumption; b. second means for measuring volt-ampere consumption coupled to the means for measuring watt consumption; c. third means for calculating a frequency-domain power factor parameter comprising a function of a ratio of watt-hours to volt-ampere-hours coupled to receive a data signal from the first means and the second means; and d. fourth means for adjusting the power factor parameter in a predetermined manner related to the non-fundamental currents and non-fundamental voltages. - View Dependent Claims (2, 3, 4, 5)
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Specification