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Journal ArticleDOI

The Application of the Current Comparator in Instrumentation for High Voltage Power Measurements at Very Low Power Factors

Eddy So
- 01 Jan 1986 - 
- Vol. 1, Iss: 1, pp 98-104
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TLDR
In this article, a current comparator is applied to several auxiliary instruments which enable accurate high voltage power measurements to be made at very low power factors using precision wattmeters and precision bridges.
Abstract
A current-comparator technique is applied to several auxiliary instruments which enables accurate high voltage power measurements to be made at very low power factors using precision wattmeters and precision bridges. The instruments include a high-voltage active-divider with a nominal output voltage of 100 V, a high-voltage inductive-quadrature-current reference source with current output ranges of 1 mA, 2 mA, and 10 mA, and a high-voltage high-capacitive-quadrature-current reference source with current output ranges of 0.1 A, 0.5 A, and 1 A. The current comparator is used in a feedback loop to correct the magnitude and phase of the associated outputs of these instruments to an accuracy of better than ±10 ppm (parts per million) and ±10 ?rad respectively.

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Citations
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Proceedings ArticleDOI

Calibration system for electronic instrument transformers with digital output

TL;DR: In this paper, a high-accuracy system for calibration of electronic instrument transformers with digital output is described, which is based on International Electrotechnical Commission (IEC) standards 61850, 60044-8, and 61844-7.
Journal ArticleDOI

The application of the current-comparator technique in instrumentation and measurement equipment for the calibration of non-conventional instrument transformers with non-standard rated outputs

TL;DR: An overview of the development of instrumentation and measurement techniques at the National Research Council of Canada, based on current comparator technology, for calibration of nonconventional instrument transformers with nonstandard rated outputs, is presented in this paper.
Journal ArticleDOI

A computer-controlled load loss standard for calibrating high-voltage power measurement systems

TL;DR: In this article, a computer-controlled load loss standard, based on the current-comparator technique, for calibrating high-voltage power measurement systems is described, which can be made at any power factor from zero lag through unity to zero lead, positive or negative power, at voltages up to 200 kV, currents up to 1000 A, and 50 or 60 Hz.
Journal ArticleDOI

No-load loss measurements of power transformers under distorted supply voltage waveform conditions

TL;DR: The problem of correcting the results of no-load loss measurements of power transformers for the effect of distorted supply voltage waveform on the magnetic flux in the core and hence on both the hysteresis and eddy current loss components of core losses is presented.
Journal ArticleDOI

An optically isolated hybrid two-stage current transformer for measurements at high voltage

TL;DR: The development of a high-voltage current measurement system for on-site/in-situ calibrations in power systems and the uncertainty of the current-ratio measurement is estimated to be less than 100middot10-6 both in-phase and quadrature.
References
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Journal ArticleDOI

A Wideband Sampling Wattmeter1

TL;DR: In this paper, the design and operation of a wideband sampling wattmeter capable of measuring distorted power signals with fundamental frequencies from 1 Hz to 10 kHz and harmonics up to 100 kHz is described.
Journal ArticleDOI

The Development and Performance of Current Comparators for Audio Frequencies

TL;DR: In this article, the design and construction of five different multiratio current comparators developed for use at audio frequencies is presented, and the effectiveness of the various shields on the reduction of the current null detector error over the operating frequency range is shown.
Journal ArticleDOI

The development of the current comparator, a high-accuracy A-C ratio measuring device

TL;DR: In this paper, a 2,000-amp (ampere) feed-through current comparator is described, and test results are given which indicate that its over-all accuracy at 60 cps (cycles per second) is better than 0.2 ppm (part per million) for all ratios from 1:1 to 400:1, irrespective of distribution of the primary winding.
Journal ArticleDOI

A Transformer-Ratio-Arm Bridge for Measuring Large Capacitors Above 100 Volts

TL;DR: In this paper, a high-voltage bridge suitable for measuring capacitance ratios up to a million to one is described, which is realized by cascading a two-stage current transformer to a bridge based on the current comparator principle.
Journal ArticleDOI

The Development of an Automatic-Reversing Differential Thermal Wattmeter

TL;DR: In this paper, a differential thermal wattmeter for the precision measurement of power at audio frequencies is described, which has a linear scale, a resolution of 10 ppm, and a direct reading accuracy of 30 ppm in the 50-1000Hz frequency band.
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