Harmonic-adjusted power factor meter
US5298856A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1992 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Oct 6, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R21/006
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 nonfundamental currents and voltages. The resulting harmonic-adjusted volt-ampere-hour measurement is used to calculate a harmonic adjusted power factor measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.