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Journal ArticleDOI

A Fast Response Device for Measurement of Power, Reactive Power, Volt-Amperes and Power Factor

01 Jan 1971-IEEE Transactions on Power Apparatus and Systems (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 90, Iss: 1, pp 331-338
TL;DR: In this paper, a solid state device using sampling techniques is described for measurement of power system quantities such as power, reactive power, voltamperes and power factor, and an output voltage linearly proportional to the above quantities is provided for continuous control and recording purposes.
Abstract: A solid state device using sampling techniques is described for measurement of power system quantities such as power, reactive power, voltamperes and power factor. An output voltage linearly proportional to the above quantities is provided for continuous control and recording purposes. The speed of response is less than one cycle.
Citations
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Patent
03 Nov 1980
TL;DR: In this article, an analog integrator for computing the integral of the voltage and of the current over a selected period of a voltage waveform is presented, and means including a digital microprocessor and a comparison circuit are provided for generating a voltage level equal to the magnitude of either current integral or the voltage integral.
Abstract: An electronic meter is disclosed, for measuring functions such as power and energy of an alternating current and voltage. For measuring electrical energy, the meter includes an analog integrator for computing the integral of the voltage and of the current over a selected period of the voltage waveform. Means including a digital microprocessor and a comparison circuit are provided for generating a voltage level equal to the magnitude of the current integral or the voltage integral. In this manner, the microprocessor determines the value of the voltage or current integral. Since the integral of a sinusoidal waveform is related to its amplitude and to the power factor, the microprocessor can make a computation of energy from the values of the voltage and current integrals.

30 citations

Journal ArticleDOI
TL;DR: In this article, a circuit for fast amplitude detection of constant period sinusoidal signals is proposed, where amplitude information is taken by several sample pulses in each half period and the sampled voltage level is held and equalized to signal amplitude by a weighting function amplifier.
Abstract: A circuit for fast amplitude detection of constant period sinusoidal signals is proposed in this paper. Amplitude information is taken by several sample pulses in each half period and the sampled voltage level is held and equalized to signal amplitude by a weighting function amplifier.

19 citations

Journal ArticleDOI
TL;DR: In this paper, a fast response detecting method of mean value of power system quantities such as, voltage, current, power, torque angle and shaft speed deviation is proposed, which is linearly proportional to the input signal.
Abstract: A fast response detecting method of mean value of power system quantities such as, voltage, current, power, torque angle and shaft speed deviation is proposed. The detected value, which is linearly proportional to the input signal, represents the mean value of each half cycle of the input signal that is held as a dc voltage as soon as that half cycle is over. The detection is stable against the random noise included in the signal, and does not have drooping characteristic.

16 citations

Journal ArticleDOI
TL;DR: In this paper, a Hall effect transducers are used to measure real and reactive power of an induction machine as it makes the transition between motor and generator. And the basic theory of these transducers is presented.
Abstract: Design details are given for a laboratory instrument which will measure real and reactive power using Hall effect transducers. The basic theory of these transducers is presented. Examples of transient operation are given. One particularly interesting result is the variation in real and reactive power to an induction machine as it makes the transition between motor and generator.

7 citations

References
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Journal ArticleDOI
TL;DR: In this article, a transistorized relay was installed to predict generation instability resulting from major system disturbances, which can be used to initiate corrective measures, such as generation tripping or dynamic braking, to maintain stability.
Abstract: A transistorized relay recently installed to predict generation instability resulting from major system disturbances is described. The relay can be used to initiate corrective measures, such as generation tripping or dynamic braking, to maintain stability. Several advantages over the present methods of initiating corrective action are obtained by use of this relay.

5 citations

Journal ArticleDOI
Abstract: A phase-angle measuring device is described which has a response time of one cycle of the signals whose phase angles are being measured. It has an adjustable full scale range which allows high-accuracy readings of small phase angle changes. An output is provided for continuous, fast response recording of phase angle changes suitable for use on an oscillograph. Some test results using the device are shown.

5 citations

Journal ArticleDOI
TL;DR: In this article, a fast response phase angle measuring device which measures the phase angle twice in the cycle has been developed, and the output is obtained just after completion of phase measurement with pro-cycle memory until that instant.
Abstract: A fast response phase angle measuring device which measures the phase angle twice in the cycle has been developed. The output is obtained just after completion of phase measurement with pro-cycle memory until that instant. Full-scale adjustments are possible for smaller angular variations.

4 citations

Journal ArticleDOI
TL;DR: In this paper, the double-line-frequency term is used to indicate power, var and volt-amperes continuously and simultaneously on three meters, the indicating signals being suitable for accurate analog-to-digital conversion for telemetering over long distances.
Abstract: Present-day methods for the measurement and telemetering of active power and reactive volt-amperes (var) are, in general, based upon the zero-frequency term produced by the multiplication of two signals corresponding to the line voltage and the line current. Although these methods are usually satisfactory for local metering, various problems are presented when telemetering over long lines is considered. This paper suggests the use of the double-line-frequency term which is also produced by this multiplication. With suitable phase sensitive rectification this term can be made to indicate power, var and volt-amperes (VA) continuously and simultaneously on three meters, the indicating signals being suitable for accurate analog-to-digital conversion for telemetering over long distances. First experimental results show an accuracy of one per cent for a wide range of resistive and reactive loads, and for a voltage variation of 40 per cent. A discussion of factors affecting the accuracy of the method is given in the Appendix.

1 citations