http://ieeexplore.ieee.org/iel5/5247218/5251870/05251902.pdf

Suggested definition of reactive power in nonsinusoidal systems and Reactive-power definitions and power-factor improvement in nonlinear systems

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.

Electronic kilowatthour meter

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.

Fast amplitude detection for constant period sinusoidal signals

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.

Fast response detection of mean value of power system quantities

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.

Hall Effect Measurement of Real and Reactive Power in a Faraday Machines Laboratory

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.

P. C. Majhee

Papers

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