This tutorial paper discusses the drawbacks of the definitions of various types of powers found in the IEEE Standard Dictionary of Electrical and Electronics Terms (IEEE Std. 100-88). With the exceptions of instantaneous power and active power, all remaining kinds of "powers" are nonphysical. The concept of power factor in polyphase circuits is ambiguous. Examples that illustrate the shortcomings of many power definitions are included. The impact of these definitions on current power/energy metering practices are discussed. It is recommended that some definitions be either changed or eliminated from the IEEE Dictionary. >

Discussion of power definitions contained in the IEEE Dictionary

A generalized procedure to obtain the probabilistic model of power system harmonic current injection and propagation is presented. The model takes into account random variations of both the operating modes as well as the configuration of nonlinear loads connected to a distribution feeder. The method is illustrated by an example of a bus having linear as well as nonlinear loads of different types. Potential applications of the model are also discussed.

Probabilistic Modeling of Power System Harmonics

An iterative process of computing harmonic voltage profile on a power system transmission network is presented. A method based upon frequency domain analysis is utilized in conjunction with the fundamental load flow computations. The concepts of conventional reactive power and the distortion power incorporated to determine interaction between the power system and harmonic generating sources. The model of the transmission system considered lends itself to the determination of the standing wave pattern and can be used in identifying the points of maxima and minima on the transmission line as well as the two end points. A phase shifting model of the transformer is presented for the harmonic analysis. Three examples of power transmission systems are taken to illustrate use of the algorithm. >

An iterative approach for analysis of harmonic penetration in the power transmission networks

50 utilities in the United States and Canada responded to a questionnaire survey regarding concerns about nonsinusoidal waveforms in the electric distribution network. Responses regarding instrumentation, apparent and reactive power definitions, meter errors, rates, and trends are presented and discussed.

A survey of North American electric utility concerns regarding nonsinusoidal waveforms

The sensitivity of television sets, induction watthour meters and universal motors to harmonics and fractional harmonics, as they occur in home appliances, is derived analytically and experimentally. This study shows that television sets are very sensitive to fractional harmonics. Calculations and measurements performed with single-phase watthour meters show that the harmonic torques within the aluminum disk are always positive and accelerate the disk. Universal machines are not as sensitive to voltage harmonics as compared with induction machines. The work described has been supported by the U.S. Department of Energy.

Sensitivity of Electrical Appliances to Harmonics and Fractional Harmonics of the Power System's Voltage. Part II: Television Sets, Induction Watthour Meters and Universal Machines

A mathematical nonlinear model is developed to simulate the performance of an induction watthour meter for nonsinusoidal voltage and current waves. The computation results show that for the special case where the voltage is purely sinusoidal, the measurement error causedby the nonlinear magnetic circuits is generally small unless the current wave contains a relatively large third harmonic component. However, when the voltage and current waves are both nonsinusoidal, the registration error can be relatively large even for a small voltage distortion. This is attributed not only to the nonlinearity but also to the drooping frequency response curve of the meter. In both cases, the sign of the registration error depends largely on the phase angles of voltage and current harmonics with respect to their fundamentals. A comparison shows that the computation results are consistent with the experimental ones which are available in the literature.

Harmonic Analysis Of Induction Watthour Meter Performance

This paper presents two numerical methods for computing the maximum overall rms current, and an algorithm to find the maximum peak of the total voltage on a transmission line under nonsinusoidal conditions. The only prerequisite is that the measured or calculated values of the individual harmonic voltages and line currents at one end of the line are assumed to be known. The proposed methods guarantee convergence to the global maxima of the rms current and peak voltage. The numerical algorithms are demonstrated by an example.

Computation of Maximum RMS Current and Peak Voltage on Transmission Lines under Nonsinusoidal Conditions

Efficient numerical methods are presented to determine the magnitude and location of maximum overall rms current (heating), peak voltage (insulation stress) and distortion factor on untransposed three-phase transmission lines under nonsinusoidal as well as unbalanced conditions. The methods which are an extension of recently reported algorithms, guarantee convergence to the global solution. Simulation results of an unsymmetrical three-phase transmission line are included.

Y. Baghzouz

Papers

Harmonic Analysis Of Induction Watthour Meter Performance

Computation of Maximum RMS Current and Peak Voltage on Transmission Lines under Nonsinusoidal Conditions

Maximum Heating and Insulation Stress on Untransposed Lines with Unbalanced Harmonic Distortion