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White, D. R.

Publications and source records attributed to White, D. R..

11 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Improving the PMU Standard

The Phasor Measurement Unit (PMU) is perhaps the first representational measurement widely dispersed in the electric power system. Its usefulness has been demonstrated on many occasions. It is shown in this paper that the excellent performance of the PMU is a tribute to PMU makers, and not attributable to the standards that are supposed to specify the performance. The IEEE and IEC standards illustrate, by means of a “reference model,” how a PMU can be made. Both standards base the model on two fundamental conceptual errors. Without these errors several improvements in performance could be made. The standards should be revised to remove the restrictive “guidance” that the reference model presently offers, and to correct the text so that the appropriate concepts are presented.

Phasor Measurement, reference model↗
DOE OSTI2021

“Frequency” and the PMU standard

The Phasor Measurement Unit (PMU) has revolutionized power system management by providing high-resolution, time-stamped, spatial, and temporal measure¬ments of the state of power systems. However, the standards defining the measured quantities have ambiguities that cause uncertainty, irreproducibility, and loss of interoperability during periods of change where the measurements should have the greatest value. This paper examines PMU frequency measurement to highlight the problems. It develops some suggestions for the scope and the next evolutionary improvements to the documentary standards. The aim is to improve the meaningfulness and trustworthiness of dynamic power system measurements.

Frequency, rate of change of frequency, definition↗
DOE OSTI2020

Power Factor revisited

Power factor is a term whose value can be found by dividing the power in a load to the product of the voltage and the current. It has been used as a rule of thumb to estimate the cost of the losses incurred in delivering reactive power. But it has been extremely troublesome. The same load might be penalized by some definitions, and might not by others. That is still the situation today. There have been two efforts at solution. In 1919 a committee of experts was formed to solve the problem of its definition. The effort did not succeed at producing a definition; two alternatives were recommended in the committee’s final report, but both were adopted. In 2010, IEEE issued Standard 1459 to give definitions. In this standard, definitions of power factor appear under no less than seven different headings. The problem demands solution. The matter is of considerable economic importance to power producers, consumers, and instrument makers. This paper examines the history of the topic, and explores reasons for the difficulty of definition in terms of measurement theory. It is shown that power factor is not suited to purpose. In fact, no definition can exist that will define power factor usefully for its intended economic purpose. Two alternatives are proposed.

power factror, definitions, measurement theory, IE↗
DOE OSTI2019

Dealing with Definitional Uncertainty: Better Measurements in Power Systems

Abstract—There is a relationship between the user of the result of a measurement and the act of measurement that should guide the act: the user has some specific need for the meaning contained in the result. The extent to which that need is met is a measure of the quality of the measurement. The usual metric is an uncertainty statement. This paper shows that, because of significant signal distortion, the uncertainty statement may be inappropriate outside the calibration laboratory. We propose a way to improve the situation. Better measurements are not necessarily ones with faster response or greater precision: the important point is that they meet the needs of the user. They are “fit for purpose.” The solution proposed here affects both the instrument designer and the user. It requires that additional information regarding uncertainty accompany all result values (not just those done in the calibration laboratory), and it requires changes to the way the results are handled by the user. The paper concentrates on the electric power system, but it is hoped that the ideas can be applied more broadly to field measurements.

measurement theory, Uncertainity, definitional unc↗
NASA NTRS1987

Development of a semi-autonomous service robot with telerobotic capabilities

The importance to the United States of semi-autonomous systems for application to a large number of manufacturing and service processes is very clear. Two principal reasons emerge as the primary driving forces for development of such systems: enhanced national productivity and operation in environments whch are hazardous to humans. Completely autonomous systems may not currently be economically feasible. However, autonomous systems that operate in a limited operation domain or that are supervised by humans are within the technology capability of this decade and will likely provide reasonable return on investment. The two research and development efforts of autonomy and telerobotics are distinctly different, yet interconnected. The first addresses the communication of an intelligent electronic system with a robot while the second requires human communication and ergonomic consideration. Discussed here are work in robotic control, human/robot team implementation, expert system robot operation, and sensor development by the American Welding Institute, MTS Systems Corporation, and the Colorado School of Mines--Center for Welding Research.

Jones, J. E.↗
NASA NTRS1976

Apollo Experiment Report: Lunar-Sample Processing in the Lunar Receiving Laboratory High-Vacuum Complex

A high-vacuum complex composed of an atmospheric decontamination system, sample-processing chambers, storage chambers, and a transfer system was built to process and examine lunar material while maintaining quarantine status. Problems identified, equipment modifications, and procedure changes made for Apollo 11 and 12 sample processing are presented. The sample processing experiences indicate that only a few operating personnel are required to process the sample efficiently, safely, and rapidly in the high-vacuum complex. The high-vacuum complex was designed to handle the many contingencies, both quarantine and scientific, associated with handling an unknown entity such as the lunar sample. Lunar sample handling necessitated a complex system that could not respond rapidly to changing scientific requirements as the characteristics of the lunar sample were better defined. Although the complex successfully handled the processing of Apollo 11 and 12 lunar samples, the scientific requirement for vacuum samples was deleted after the Apollo 12 mission just as the vacuum system was reaching its full potential.

White, D. R.↗
NASA NTRS1973

Study of resonance light scattering for remote optical probing

Enhanced scattering and fluorescence processes in the visible and UV were investigated which will enable improved remote measurements of gas properties. The theoretical relationship between scattering and fluorescence from an isolated molecule in the approach to resonance is examined through analysis of the time dependence of re-emitted light following excitation of pulsed incident light. Quantitative estimates are developed for the relative and absolute intensities of fluorescence and resonance scattering. New results are obtained for depolarization of scattering excited by light at wavelengths within a dissociative continuum. The experimental work was performed in two separate facilities. One of these utilizes argon and krypton lasers, single moded by a tilted etalon, and a 3/4 meter double monochromator. This facility was used to determine properties of the re-emission from NO2, I2 and O3 excited by visible light. The second facility involves a narrow-line dye laser, and a 3/4 meter single monochromator. The dye laser produces pulsed light with 5 nsec pulse duration and 0.005 nm spectral width.

Penney, C. M.↗
NASA NTRS1968

Precision bolometer bridge

Prototype precision bolometer calibration bridge is manually balanced device for indicating dc bias and balance with either dc or ac power. An external galvanometer is used with the bridge for null indication, and the circuitry monitors voltage and current simultaneously without adapters in testing 100 and 200 ohm thin film bolometers.

White, D. R.↗