Publications

Reference

NBSIR 82-2501

I iliiijliii 111 iilii I lii illiii AiiiDt jlopment of Power System

Measurements -- Quarterly Report

October 1 , 1 981 to

December 31, 1981

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Electronics and Electrical Engineering

Electrosystems Division

Washington, DC 20234

February 1 982

Issued may 1 982

Prepared for.

-QC

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' 82-2LiUl

oartment of Energy

ision of Electric Energy Systems

shington, DC 20585

19d2

NBSIR 82-2501

atioma.1. bur».a.

OJT TANl>iUtD«

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JUL 2 2 ]982

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DEVELOPMENT OF POWER SYSTEM

MEASUREMENTS -- QUARTERLY REPORT

OCTOBER 1, 198 I TO

DECEMBER 31. 1981

R E. Hebner, Editor

U.S. DEP.ARTV;ENT OF COMMERCE

National Bureau of Standards

Center for Electronics and Electrical Engineering

Electrosystems Division

Washington, DC 20234

February 1 982

Issued May 932

Prepared for: Department of Energy

Division of Electric Energy Systems

Washington, DC 20585

U.S. DEPARTMENT OF COMMERCE, Malcolm Saldrige, Secretary

NATIONAL BUREAU OF STANDARD.S, Ernest Ambler, Director

Foreword

This report is intended to summarize the progress on four technical

investigations during the fourth quarter of FY 1981. Although reasonable

efforts have been made to ensure the reliability of the data presented,

it must be emphasized that this is an interim report, so tnat further

experimentation and analysis may be performed before the conclusions

from any of these investigations are formally published. It is therefore

possible that some of the observations presented in this report will be

modified, expanded, or clarified by our subsequent research.
I
TABLE OF CONTENTS

Page

Foreword iii

LIST OF FIGURES v

Abstract 1

1. INTRODUCTION 1

2. OC FIELDS AND ION MEASUREMENTS

Project No. A018-EES 1

3. INCIPIENT FAULT DETECTION/LOCATION

Project No. A063-EES

4. TECHNICAL ASSISTANCE FOR FUTURE INSULATION SYSTEMS RESEARCH

Project No. A053-EES 6

5.

OPTICAL MEASUREMENTS FOR INTERFACIAL CONDUCTION AND BREAKDOWN

Project No. A057-EES 11

6.

REFERENCES 16

LIST OF FIGURES

Page

Figure 1. Block diagram of apparatus used to analyze electric

field waveforms 4

Figure 2. Calibration curves for the gas chromatograph-mass

spectrometer 8

Figure 3. Dual beam oscilloscope traces of simultaneous optical

(upper trace) and electrical (lower trace) pulses from

positive dc corona in SF 5 at 300 kPa 10

Figure 4. 60-Hz electric field profiles and inferred space charge

in nitrobenzene . 12

Figure 5. The electric field distributions at four different

temperatures in clean oil 14

v

DEVELOPMENT OF POWER SYSTEM MEASUREMENTS — QUARTERLY REPORT

October 1, 1981 to December 31, 1981

R. E. Hebner, Editor

This report documents the progress on four technical

investigations sponsored by the Department of Energy and

performed by the El ectrosystems Division, the National Bureau

of Standards. The work described covers the period from

October 1, 1981 to December 31, 1981. The report emphasized

measurements of ion density in air, the use of signals above

1 GHz to detect incipient faults in cables, the measurement of

the by-products which develop during partial discharge activity

in SF 5 , and the determination of the breakdown behavior of an oil-paper interface.

Key words: cables; composite insulation; dc fields; high voltage;

incipient fault; insulation; liquid breakdown; SF 5 ; space charge;

transformer oi 1 .

1. INTRODUCTION

Under an interagency agreement between the U.S. Department of

Energy and the National Bureau of Standards, the Electrosystems

Division, NBS, has been providing technical support for OOE's research

on electric energy systems. This support has been concentrated in

four areas -- the measurement of electric fields, the measurement of

the electromagnetic properties of solid insulating materials and cables,

the measurement of partial discharge phenomena in gaseous dielectrics,

and the measurement of interfacial electrostatic field distributions

and of space charge density. The technical progress made during the

quarter October 1, 1981 to December 31, 1981 is summarized in this

report

.

2. DC FIELDS AND ION MEASUREMENTS

Project No. A018-EES

The objectives of this effort are to investigate devices and

measurement techniques which may be used to characterize the electrical

environment near high-voltage dc (HVDC) transmission lines, to evaluate

methods being used for calibrating such devices, and to develop and

establish calibration facilities at NBS which will permit independent

verification of the accuracy of user cal i brati ons

.

1
By developing appropriate methods of instrument calibration, it

will be possible to compare measurements taken in the vicinity of a high-voltage transmission line with measurements taken in biological

exposure facilities. Such a comparison will be necessary in any formal or informal risk assessment.

Most of the technical effort during the reporting period was concerned with preparing reports describing investigations which were

completed during FY-81. The titles of these reports and their status

are:

"Measurement of Ion Current Density at Ground Level in the

Vicinity of High-Voltage DC Transmission Lines," R. H. McKnight,

F. R. Kotter, and M. Misakian, NBSIR 81-2410 (published Dec. 1981);

"The Measurement of Net Space Charge Density Using Air Filtration

Methods," R. H. McKnight, NBSIR 82-2486 (published Apr. 1982); and

"A Facility to Produce a Volume Containing Space Charge for Use in

Evaluating Ion Measuring Instruments," R. H. McKnight and

F. R. Kotter (approved for publication).

One project which was completed during the quarter was the

evaluation of a measuring system for determining the frequency and

magnitude of harmonics in the electric field present in ac biological

exposure facilities. These exposure systems, in the simplest form,

consist of parallel plates connected to the secondary of a high-voltage

transformer. It is important in the biological experiments that the

electric field present in the exposure region be well characterized. The

electric field can be mapped using a miniature E-field probe such as that

developed earlier at NBS. The presence of harmonic components in the field

can lead to uncertainty in experiments since capaciti vely-coupled currents

depend on the frequency of the exciting field. Minimizing such harmonics

constitutes an important part of the overall "quality control" of the

experiment. Harmonics can be enhanced by resonances between the capacitive

load presented to the high-voltage power supply by the exposure system and

the intrinsic inductance of the power supply itself. The presence of these

harmonics must be determined with the system at operating voltage, which

may be as high as 60 or 70 kV. Even simple observation of the waveform

requires a high-voltage probe and an oscilloscope.

A system which will be used in the field by NBS personnel during

evaluations of ac biological exposure facilities has been configured.

The system requirements included portability, frequency range up to

1 kHz (to include all harmonics of interest), and overall accuracy of

a few percent of the fundamental

.

2
Signals from the exposure system can be derived directly by using

voltage dividers, or by the use of capaci ti vely-coupl ed probes.

Because of current limitations in many systems, the voltage dividers

would have to be of high impedance to avoid loading effects. In

addition, the frequency response of a resistor divider would have to

be dc-?termined up to the frequency of the highest harmonic of interest.

In systems utilizing balanced excitation, two matched dividers would

have to be used in a differential scheme.

It was decided to avoid problems associated with voltage divider

measurements and to utilize instead a simple capacitive probe. In

particular, the output from the miniaturized E-field probe was used

as a signal source. This capacitive-coupled mode introduces a minimum

perturbation of the system. A schematic of the experimental configuration

used to evaluate the filter system described below is shown in figure 1.

A spectrum analysis of the derived signal can be made using

several types of equipment: spectrum analyzers, wave analyzers, or tunaole filters. Questions of cost and system portability led to the

consideration of a battery-operated tunable filter. The filter selected

was systematically evaluated in terms of bandpass, shape, gain, and

stability. These tests were done using a variety of signal sources.

A theoretical analysis of the system was also made. The results

of tnis investigation indicated that the harmonic content of the

electric field could be determined in many cases to an accuracy of a few percent, for the low-lying harmonics of interest (n<10). A much

more precise system could be designed around a spectrum analyzer.

However, such systems are substantially heavier and thus less portable

than the tunable filter. The tunable filter is expected to be adequate

for identifying malfunctioning biological exposure systems.

The system described above will be used by NBS personnel during

evaljation of biological exposure facilities.

Project personnel participated in a field day held at Project UHV

in October 1981. This field day was organized by the IEEE Working

Group on DC Fields and Ions. Emphasis was on measurement of ion-related

quantities such as ion density and vertical current density. Errors

associated with measurements of vertical current density made with

sensors located above the ground plane were determined for full-scale

sensors under the test line. The results of these experiments are consistent with those done in the laboratory at NBS.

For further information, contact Dr. R. H. McKnight, (301) 921-3121.

3
Figure 1. Block diagram of apparatus used to analyze electric field

waveforms.

4
3. INCIPIENT FAULT DETECTION/LOCATION

Project No. A063-EES

The objective of this program is to identify and, insofar as practical, remove technical barriers to the development cf a successful

incipient fault detector/locator for underground power transmission use. NBS responsibility includes conducting an experimental program that will

aid the development of an incipient fault detection/location system by

measuring the rf characteri sti cs of power cables, and evaluating the

frequency content of partial discharge pulses emanating from incipient

fault sites in a cable dielectric.

Previously, attempts had been made to detect incipient fault sites

in the cable dielectric using time domain refl ectometry (TOR)

techniques. This was not successful because of the large attenuation

of the TEM wave caused primarily by the semiconducting screening layers

of the cable. Some progress had been made with TOR using other waveguide modes with no appreciable electric field in the screening layers.

Preliminary measurements suggested successful transmission of some of

these modes in polyethylene rods (i.e., no center' conductor). The

laboratory phase of this program was then terminated before the

excitation of these modes in cables was attempted.

In the process of documenting the output of this project, and,

specifically, preparing a paper for the Waveform Recorder Seminar in

Boulder, Colorado in September 1981, a possible measurement problem

was noted, which could manifest itself in any experimental setup using

discrete sampling. In our case, a time domain function f(t) is

sampled at intervals, T, resulting in values:

f(T), f(2T), . . , f(NT).

We then take a Discrete Fourier Transform (DFT) of the sampied function,

f(t), in order to obtain the function in the frequency domain;

F(w) = Zf(nT)e-jwnT (1)

n = -00

This DFT is usually accomplished using Fast Fourier Transform (FFT)

or other specialized software [1]. In our case, we sample two time domain

functions f(t) and g(t). For example, f(t) might represent the

response of a certain length of cable and g(t), a longer lengfh. If

in both cases the same connectors and terminations are used, the

ratio of G((jj) to F(o)) will yield the transfer function of the added

length of cable.

In the case of a conventional sampling oscilloscope, we have

observed that in practice the sampling rate may drift particularly as the instrumentation is warming up. For ease of discussion we assume

5
that the sampling interval is constant and equal to T when sampling

f(t) and then drifts to a new value T' when sampling g(t). The software

however, expects the sampling Interval to be T although the data has

been sampled at intervals of T' so that

G' (o)) = Zg(nT' )e-JfiJnT^ (2)

n = -oj

where G'(o)) is the false DFT of g(t)„ If T' = aT then

G'(w) = Zg(nT' )e-j<^nT7ct (3)

n = -“

= G((Ai/a) ,

In other words, a drift in the sampling rate results in a shift in the

frequency domain. The problem becomes readily apparent when the ratio

Qi' {(m) /¥ {(ii) is evaluated for the case when f(t) and g(t) represent

the response of the identical length of cable. If the sampling interval

T' is smaller than T (a<l), the ratio will indicate hi gh-f reqenucy

roll off.

We believe that this measurement problem caused by drift is common

to all sampling oscilloscopes. Proper experimental procedure could

eliminate or at least minimize the effect. A stable time standard

could be used to calibrate the oscilloscope's time base during each

trace, for example. It should also be possible to eliminate the effects

of the drift in software.

This effect is not purely academic in that it has produced an observable modification of our results. The problem is described in a paper presented at the Waveform Recorder Seminar mentioned above, and

the theoretical aspects are discussed in a forthcoming paper.

For further information, contact Cr. W. E. Anderson, (301) 921-3121

4. TECHNICAL ASSISTANCE FOR FUTURE INSULATION SYSTEMS RESEARCH

Project No. A053-EES

The objective of this project is to develop diagnostic techniques

to monitor, identify, and predict degradation in future compressed gas

electrical insulating systems under normal operating conditions. Focus

is on the fundamental information and data needed to improve test design

and performance evaluation criteria. The investigation of partial

6
discharges (corona) in gaseous dielectrics is emphasized. This

phenomenon gives rise to degradation of the gas under high electrical

stress and may lead to breakdown. Measurement of partial discharge

inception in highly nonuniform fields may prove to be a preferred

method to determine dielectric strength of electronegative gases.

Planned activities for FY-82 include: 1) complete an archival

paper on basic mechanisms of corona inception in SF 5 under ac and dc

conditions; 2 ) investigate the wavelength dependence of photon-induced

positive corona inception in SF 5 ; 3) continue measurements of power

dependence of the rates of oxyfluoride and water vapor production from corona discharges in SF 5 and report the results in a conference and

an archival paper; 4) explore the i"easibility of new methods to measure

field enhanced collisional detachment of negative ions in SF 5 and other

e I ectronegati ve gases; 5) improve the accuracy of quantitative analysis

of trace gases such as H 2 O in SF 5 and other gaseous dielectrics using a gas chromatograph-mass spectrometer , GC/MS, and extend the measurements

of the effects of trace H 2O on corona characteri sti cs and relative

dielectric strength of the gas; and 6 ) complete an archival paper on compilation and evaluation of electron swarm data in molecular electronegative gases. In addition, there was an incomplete investigation in

FY-81, namely, the measurement of light emission from corona pulses in

SF 5 and correlation of results with electrical detection of corona pulses.

Progress was made during the reporting quarter on all of the above

activities except activity 2. A paper entitled "Mechanisms for

Inception of DC and 60-Hz AC Corona in SF 5

" was presented at a special

symposium on corona and non-spark discharges which was held during the

1981 IEEE Conference on Electrical Insulation and Dielectric Phenomena.

This paper was also submitted for publication in the IEEE Transactions

on Electrical Insulation [2], thus completing activity 1 above. A survey of electron swarm data for electronegative gases [3] has been

completed and submHted to the Journal of Physical and Chemical

Reference Data, indicating thereby the completion of activity 6 . As

part of activity 3., preparation was begun on a paper giving our results

on corona-i nduced decompositon of SF 5 to be presented at the Third

International Symposium on Gaseous Dielectrics. In this report we highlight technical information acquired as a result of activity 5 and

measurements cf correlation between optical and electrical pulses from corona in SF 5

.

Emphasis was given during the past reporting period to performing

measurements and tests needed to evaluate the performance and

sensitivity of the gas chromatograph-mass spectrometer for quantitative

analysis of oxyfluoride content in SF 5

. Improvements were made in the

data ana'vsis procedure which permit more reliable determination of

the absolute concentrati ons of SOF 2 and SO2

F

2 , particularly at levels

below 10 ppm by mole fraction. An example of the information obtained

is shown in figure 2. Plotted here on a log-log scale is the measured

7
Figure 2 . Calibration curves for the gas chromatograph-mass spect rometer.

Shown are data for SOF2 and SO2F2 at the indicated mass-tocharge ratios. The open symbols correspond to areas under

chromatogram peaks calculated using software provided with

the GC/MS. The closed symbols correspond to peak-height

determi nations

.

8

mil

I

I

I

I

I

ml
response from the mass spectrometer output versus concentration

of SOF2 in SFg for the ions S0F2'^ and S02F’'’ having mass-to-charge

ratios, m/e, respectively, in a.m.u. of 06 and 83 . These ions give the

highest sensitivities for detection of SOF2 and SO2F2. The different

symbols correspond to two different methods of data analysis. The

open symbols correspond to calculated areas under the peaks in the

chromatograms using software provided with the system. The closed

symbols are calculated chromatogram peak heights which show less

scatter, particularly at lower concentrations, and come closer to

fitting a straight line with a slope of 1.0, thereby demonstrating

linearity of response. The fact that the response proved to be linear' over the range of conditions normally encountered in analysis of SF5

is significant in that it greatly simplifies the GC/MS calibration

procedure.

Reanalysis of chromatograms from our previous experiments on decomposition of SF5 in corona discharges revealed the presence of

SOF4. This species is postulated to be an intermediary in the product

production of SO2F2 via the reaction

SOF4 + H2O > SO2F2 + 2 HF. ( 4 )

The detection of this species has been complicated by the fact that its

elution time in the chromatographi c column is only slightly longer than

that for SO2F2. In fact, its presence in the column leads to a broadening

of the SO2F2 peaks due to the occurrence of reaction ( 4 ) in the column.

Oetermi nati on of SO2F2 concentrations from calculations of areas under

the peaks can lead to serious errors due to overlap with the SOF4 features.

Use of peak heights instead of areas allows considerable reduction in the

uncertainties associated with quantitative measurement of SO2F2.

It has not been possible to obtain reliable standard samples of

SOF4 in SF5 for use in calibration of the GC/MS. Thus, an indi.''ect

method of calibration for this species has been investigated wheneby

degraded SF5 containing SOF4, H2O, and SO2F2 is analyzed before and

after the sample is left undisturbed for an extended period (>8 h).

The decrease in SOF4 concentration due to reaction ( 4 ) above corresponds

to an increase in SO2F2. Therefore, from a calibration using a standard

SO2F2 sample, together with a determination of the increase in SO2F2 from

reaction ( 4 ), it is possible to make a reasonable estimate of the SOF4

content

.

Further investigations were carried out on correlation between

electrical and optical emission pulses from corona discharges in SF5.

The optical emission was detected with a fast photomultiplier tube and

the electrical current pulses were detected with a time resolution oT

~1 ns. Both signals were recorded simultaneously with a dual beam

oscilloscope. The results, as indicated by the oscilloscope traces

shown in figure 3 , reveal a high degree of correlation in time between

9
Figure 3. Dual beam oscilloscope traces of simultaneous optical

(upper trace) and electrical (lower trace) pulses from

positive dc corona in SF 5 at 300 kPa.

ii'

111

'

10
the optical and electrical signals. They appear to occur simultaneously

to within ±2 ns. This observation is significant because it indicates

that the electrical signals can be used as triggers for time resolved

measurements of optical pulses and vice versa.

During the next quarter, a conference paper will be prepared for

inclusion in the Proceedings of the Third Internati onal Symposium on Gaseous Dielectrics to be held in Knoxville, March 7-11, 1982. Some of our recent results on measurement of the power dependence of gaseous

by-product production rates from corona in SF 5 will be discussed,

together with our observations of correlations between changes in the

pulse height distributions of positive corona pulses and buildup of

contaminant and decomposition product concentrations. More measurements

will be carried out on decomposition of SF 5 in corona. Emphasis will

be given to determination of SOF 4 concentrations and the effect which

this species has on measuremert of SO2F 2

. A technique for continuous

calibration of the GC/MS will be set up and tested. Measurements of

effects of changing polarity on corona-induced decomposition will also

be considered, together with extension of present measurements to higher

discharge power* levels and other gas mixtures such as SF 5 -N 2

. Preliminary

investigations will be carried out of wavelength dependence of electron

avalanche rate in SF 5 for a positive-point-plane gap irradiated with a tunable dye laser or a filtered ultraviolet lamp. The purpose of this

study is to determine the minimum photon energy needed to initiate

corona via photodetachment of negative ions present in high pressure

(>100 k.Pa) SF 5.

For further information, contact Dr. R. .1. Van Brunt, (301) 921-3121 .

5. OPTICAL MEASUREMENTS FOR INTERFACIAL CONDUCTION AND BREAKDOWN

Project No. A057-EES

The objective of the project is to develop measurement techniques

to determine the interfacial phenomena which influence the electrical

breakdown character! sti cs of composite insulation systems. In particular, the role of space charge in electrical breakdown is being

investigated. Specific attention has been placed on performing Kerreffect, el ect ro-opti cal measurements of the electric field in transformer

oil between parallel plates under a variety of contaminations and at

different temperatures . These techniques will then be applied to more

complicated transformer oi 1 -pressboard or paper systems.

It is recognized that contamination and space charge may lower the

electrical strength of a system. Contaminants such as particles may

reduce the breakdown voltage, and space charge may produce field

intensifications near one electrode thereby enhancing the probability

of breakdown. Past quarterly reports have dealt with the measurement

of the electric field in both clean and heavily contaminated transformer

oil from room temperature to around 70'^C. The contaminated oil of

greatest interest was the oil from a tailed transformer.

11
o

gUio U3d S39(1VH3 30 U38l^nN

N

ItM

fM

'V. ”S

tuN

( gUio/o)d'AllSN3a 30aVH0 30VdS

g

H

o

GU

I

I

3aONV

UBSMON 39Nid3

3Q0H1V0

z

g

Iz

(7) o

Figure

4.

60-Hz

electric

field

profiles

and

inferred

space

charge

in

nitrobenzene.

The

field

profiles

have

been

inferred

from

the

intensity

information

obtained

from

the

light

measurement

system.

The

fringe

number

refers

to

light

or

dark

areas

in

the

Kerr-effect

intensity

profile.
Previous measurements had shown that, in clean oil, space charge

distortion of the uniform field between parallel plates was less than

about 5%, It was expected that the contaminated oil might show more

space charge, but such was not the case. From room temperature to 68“C,

the uniform field was distorted no more than about 6%. It was pointed

out at that time that the possibility of systematic thermal optical

effects which would produce such an apparent space charge could not be

ruled out. Even so, a 6% distortion of the field was an upper bound

and was not considered serious in terms of lowering the electric strength

of transformer oil by field enhancement. Such a distortion is small

compared to space-charge field distortions found in liquids like

nitrobenzene.

Earlier in this work, the measurement system's performance was verified by determining the electric field in nitrobenzene between

parallel plates. In figure 4, plots are shown which were inferred from

the observed Kerr-effect intensity profiles obtained with the measurement

system. In this figure Em is the lowest field which would be requir^ad

to make the Kerr cell transparent. Because the field is not uniform,

the amount of space charge present is determined from Poisson's equation

p = e dE/dZ. It should be noted that the space charge is positive and

saturates at the level above 400 nC/cm3. These measurements demonst''ate

that the system does respond to field distortions. Since previous

transformer oil data suggested the possibility of more space charge as the temperature increased, it became important to further extend these

measurements to higher temperatures.

Measurements in clean transformer oil were extended to just above

100°C. In figure 5 plots are shown of the electric field as a function

position between parallel plates. These profiles are for the positive

peak of a 60-Hz waveform at oil temperatures of 76, 85, 95, and 107®C.

Each curve represents an accumulation of the information for 3000 to

4C00 cycles of the 60-Hz waveform in order to average out the effects

of turbulence. The electric field is normalized to the field's average

value. The applied field is on the order of 60 kV/cm with a plate

spacing of about 0.6 cm.

Although the 76 and 86°C electric field profiles show an enhancement at the cathode, all the field nonuniformities can be

contained with 10% of the field maximum. In the 95"^C data there is a sharper apparent field enhancement at the cathode, which is somewhat

larger than 10% of the field maximum. It is believed that this apparent

enhancement is due to optical effects and not space charge because the

same enhancement did not occur with the 107*^0 profile. It is speculated

that there is a systematic effect because of non-equilibrium, misalignment,

heating, or a combination of processes, which gives rise to the apparent

enhancement so near the plate. This matter will be investigated in the

future.

13
NORMALIZED

ELECTRIC

FIELD

- d/2 0 d/2

(CATHODE) (ANODE)

POSITION, 2

Figure 5. The electric field distributions at four different temperatures

in clean oil. Note that the vertical scale in this figure is

expanded to accentuate any effects of space charge.
It must be stressed that if the apparent field enhancement persisted

throughout all the measurements there would be an objection to ignoring

these sharp peaks near the anode. But since it is not observed in the

107°C data, it is unlikely that space charge is responsible. If a 10%

field distortion were present on the average between the plates this

would correspond to a space charge ot 2 nC/cm3.

Although these data did not suggest significant field distortion

due to space charge it is not proposed that space charge has no effect

in lowering the breakdown strength of transformer oil. The data so far suggest that any space-charge field distortions are small, so that

the strength cannot be significantly lowered by field enhancement. It is intended that these measurements will be extended to higher

temperatures with controlled levels of contamination in the future.

Preparations are also being made to include investigations of the effects

of an interface.

For further information, contact Or. E. F. Kelley, (301) 921-3121.

15
6 . REFERENCES

[1] W. E. Anderson and J. D. Ramboz, 1980 Annual Report: Technical

Contributions to the Development of Incipient Fault Detection/Location

Instrumentation, Nat. Bur. Stand. (U.S.), NBSIR 31-2235, 130 pages.

(Jan. 1981).

[2] R. J. Van Brunt and M. Misakian, Mechanisms for Inception of DC

and 60-Hz AC Corona in SF 5 , IEEE Trans. Elec. Insul., Vol . EI-17,

No. 2, pp. 106-120, Apr. 1982.

[3] J. W. Gallagher, E. C. Beaty, J. Dutton, and L. C. Pitchford,

A Survey of Electron Swarm Data for Electro-Negative Gases,

(submitted for publication in J. Phys. Chem. Ref. Data).

16
MBS«]14A (REV. 2-9C) U.S. DEPT. OP COMM. 1 . BIBLIOGRAPHIC DATA

SHEET fSee inswciicns)

PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. NBSIR 82-2501

3. Publication Date

May 1982

4. TITLE AND SUBTITLE

Development of Power System Measurements -- Quarterly Report

October 1,- 1981 to December 31, 1981

5. AUTHOR! S)

i R.E. Hebner, Editor

1 6. PE.RFORMING ORGANIZATION (If joint or other than NBS, see instructions) 7. Cpntract/Grant No.

NATI0N.4L BUREAU OF STANDARDS EA77-A-01-6010

1 DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

i»ASHINGTOM, D.C. 20234 Quarterly

10/1/81 - 12/31/81

3. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City. State. ZIP)

Department of Energy

Division of Electric Energy Systems

Washington, DC 20585

I 10. SUPPLEMENTARY NOTES

!

1 Document describes a computer program; '3F-I85, FlPS Software Summary, Is attached.

11. ABSTRACT (A 200-word or /ess faciual summery of most si gnificant in formation, if document includes a significant

bi bl io graphy or literature survey, mention it here)

This report documents the progress on four technical investigations sponsored by

the Department of Energy and performed by the Electrosystems Division, the

National Bureau of Standards. The work described covers the period October 1, 1981

to December 31, 1981. The reper't emphasized measurements of ion density in air,

the use of signals above IGHz to detect incipient faults in cables, the measurement

of the by-products which develop during partial discharge activity in SFg, and the

determination of the breakdown behavior of an oil-paper interface.

12. '<EY WORDS (S/x to twelve entries; aipnaoetical order; capitalize only proper names; and separate <ey woras by semicolons;

cables; composite insulation; dc fiolds; high voltage; incipient fault;

insulation; liquid breakdown; SFg; space charge; transformer oil.

13. availability

3 Uni imited

I

; For Official Distribution. Do Not Release to NT'S

'

i Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402. ^ Order From National Technical Information Service (NTIS), Sormgfield, VA. 22161

14. NO. OF -

j PRINTED PAGES

15. Price

36 . 00

_SCCmm-CC 5343-=3C