ANSI/IEEE Std 664-lQQn

IEEE Guide on the Measurement of the Performance of Aeolian Vibration Dampers for Single Conductors

Published by The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, New York IOOl7 October 1 6 , 1980 SH07724

IEEE Std 664-1980

IEEE Guide on the Measurement of the Performance of

Aeolian Vibration Dampers for Single Conductors

Sponsor Transmission and Distribution Committee of the

IEEE Power Engineering Society

o Copyright 1980 by

The Institute of Electrical and Electronics Engineers, Inc

N o part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise,

without the prior written permission of the publisher.

Joseph L. Koepfinger, Chairman

William E. Andrus C. N. Berglund Edward J. Cohen Warren H. Cook David B. Dobson R. 0. Duncan Charles W. Flint

Approved December 14,1978

IEEE Standards Board

Irvin N. Howell, Jr, Vice Chairman

Ivan G. Easton, Secretary

Jay Forster Donald T. Michael Ralph I. Hauser Voss A. Moore Loering M. Johnson William S. Morgan Irving Kolodny Robert L. Pritchard William R. Kruesi Blair A. Rowley Thomas J. Martin Ralph M. Showers John E. May B. W. Whittington

Foreword

(This Foreword is not a part of IEEE Std 664-1980, IEEE Guide on the Measurement of the Performance of Aeolian Vibration Dampers for Single Conductors.)

This guide has been prepared jointly by the IEEE Working Group on Conductor Vibration and Galloping and the CIGRE (Conference Internationale des Grandes Reseaux Electriques a Haute Tension, International Conference on Large High Voltage Electric Systems) study committ,ee 22 - Overhead Lines -Working Group 01 on Mechanical Oscillations. I t is the second of a series planned for standardizing the measurement of the inherent energy characteristics of overhead conductors, the performance of aeolian vibration dampers and ultimately the prediction of the vibration ampli- tudes and the dynamic mechanical strain in conductors resulting from wind induced vibration. An objective of these guides is to establish universally accepted procedures and parameters for develop- ing methods for controlling aeolian vibration.

The membership of the IEEE technical working group was:

A. T. Edwards, Chairman

R. E. Brokenshire J. E. Chapman R. L. Dowdy A. Pue Gilchrist A. R. Hard A. C. Pfitzer

C . B. Rawlings R. L. Retallack A. S. Richardson J. B. Roche T. 0. Seppa R. B. Siter

J. Watkins

At the time of approval of this guide the Working Group 01 Mechanical Oscillations of CIGRE Study Committee No 22, Overhead Transmission Lines, consisted of the following members :

M. Ervik (Norway), Chairman

H. W. Adams (USA) A. Berg (Norway) A. Boelle (France) W. Calshem (Sweden) R . Claren (Italy)

M. Cojan (France) A. T. Edwards (Canada) A. R. Hard (USA) L. Mocks (West Germany) A. Petterson (Sweden)

M. J. Tunstall (Great Britain)

Contents

SECTION PAGE

1 . Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3 . Mechanical Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 . Measurement Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 . Testprocedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2 . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

FIGURE

Fig 1 Vibration Damper Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

APPENDIXES

Appendix A Sample Test Results Vibration Damper Power Dissipation . . . . . . . . . . . . . . . . . 11

Appendix B List of Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Appendix C Additional Notes on Power Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2

IEEE Guide on the Measurement of the Performance of

Aeolian Vibration Dampers for Single Conductors

1. Scope

The basic engineering approach to the control of vibration of overhead conductors is to com- pare, at an acceptable amplitude, the wind power input with the power dissipated by the conductor and supporting structures and hard- ware. The difference between these two quanti- ties is the amount of power that ideally should be dissipated by a vibration damping system, when attached to a single conductor at one or more appropriate locations. IEEE Std 563-1 978, Guide on Conductor Self-Damping Measure- ments, sets out the procedure for determining the power dissipated within the conductor and is a basic reference for this guide.

This guide describes the procedures for deter- mining the performance of vibration damping systems. It is hoped that the guide will assist in standardizing the methods involved and that it will result in more reliable basic information on damper dissipation characteristics, on a basis that is consistent with the technical require- ments, and that is universally recognized and accepted. A third guide is planned which will outline the procedures to be used for limiting conductor vibration to safe levels. This will in- corporate the information on the inherent damping within conductors, provided by IEEE Std 563-1978, and the data on damper charac- teristics, based on the suggested methods out- lined in this guide.

A list of symbols is included in the Appendix.

2. References

[ I ] IEEE Std 563-1978, Guide on Conductor Self-Damping Measurements.

[ 21 Standardization of Conductor Vibration Measurements. IEEE Transactions on Power Apparatus and Systems. vol PAS-85, No 1, Jan 1966.

3. Technical Considerations

While the damping characteristics of a number of types of dampers can be determined directly from forced vibration methods, that is, by vibrating them directly rather than on a con- ductor, other types of dampers utilize the damp- ing inherent in conductors as part of the dissipa- tion system, and thus the direct method is not applicable, if complete information is required on the damper characteristics as installed on a transmission line. There are other damper types with which it is simply not practical to use the direct method because of their principle of operation, dimensions, or general arrangement. Since the engineering objective is to quantify the power dissipated by a damper installed on a conductor as a system, it is recommended that the measurement be performed on a laboratory span utilizing the conductor for which the damping system is intended. This basic system will provide uniformity in method for determin- ing darnper characteristics and flexibility in accommodating any type of damper, regardless of its mode of operation. The basic system is, therefore, preferred over the direct forced method. The basic procedures for setting up the span, the terminations and conditioning of the conductor, etc, the excitation system, and the methods for determining the power dis- sipated, are described in IEEE Std 563-1978, which shall be used in conjunction with this guide.

7

IEEE Std 664-1980 IEEE GUIDE ON THE MEASUREMENT OF THE PERFORMANCE OF

The problem of measuring the energy dissipa- tion of a conductor, or of a damper, is far from being a simple exercise. For example, when a damper is attached to a conductor in a span, it usually modifies the mode-shape of the loop in which it is attached. Not only is the amplitude of the loop changed as compared with a free loop, that is, without damper, but the loop length is either shortened or lengthened depend- ing on the characteristics of the damper for the particular frequency under consideration. Under some conditions, the damper may force a node at its point of attachment. Thus the conductor dissipation in the damper loop may be different from that in a free loop at the same amplitude. In addition, due to the high level of damping normally present when a damper is applied to a conductor span, modes, other than the one resonated, are excited; these complicate the determination of the dissipation of the damper. Furthermore, the vibration amplitude of the conductor damper system tends to be some- what unstable, due in part to some damper types having nonlinear response characteristics with amplitude. A principal objective of this guide is to provide methods of determining damper characteristics which are reasonably practical and economical rather than being fully substantiated theoretically. It is a further objective to encourage interested organizations to provide facilities for undertaking measure- ments. The methods recommended in this guide are expected to provide greatly improved under- standing and procedures for designing vibration control. The recommended methods will not lead to errors that are incompatible with the present technical position of the aeolian vibra- tion problem.

Another objective of this guide is to provide information on the resulting conductor dynamic strain at terminating clamps. This is the measur- able parameter most closely related to the fatigue life of the conductor and determines whether or not the vibration levels are safe. Since precise location of the maximum strain is not predictable, and since the relationship be- tween bending amplitude and conductor strain [2]' is reasonably well established and accepted, it is recommended that bending amplitude be determined simultaneously with the damper performance. For this purpose, it is essential

'The numbers in brackets correspond to the refer- ences listed in Section 2 of this guide.

8

that the conductor be rigidly supported at the termination blocks, rather than by flexure members. See IEEE Std 563-1978.

The bending amplitude is defined as the total excursion or displacement measured relative to the clamp and at a point 90 mm from the last point of contact between the clamp and the conductor. The matter of damper fatigue is not a subject of this guide. The information provided for determining safe vibration levels, however, can also be used for setting conditions under which dampers must operate without failure. In this connection, it is helpful for analyzing the results to measure the amplitude of the damper clamp and to include this information in the summarizing table.

4. Measurement Methods

Two forced vibration methods are available for measuring the power dissipated by the con- ductor and damper system (see IEEE Std 563- 1978). These are the power method and the standing wave method and both are suitable for the purposes of this guide. In both methods, the conductor system is forced into resonance by an electrodynamic-vibration generator. For this application, the generator is located in the first vibration loop at one end of the test span.

In the power method, the power input is measured by determining the product of the exciting force and the conductor velocity at the point of application of the force. The power dissipated by the damper system under test will be the total power input into the conductor system minus the power dissipated by the con- ductor alone, that is, without the damper at- tached, as follows:

where Pd = power dissipated due to the damper PT = power dissipated by the damper and con-

ductor as a system Pc = power dissipated by conductor span and

termination, etc, without the damper

In the standing wave method, the power trans- fer from one end to the other of the conductor system is determined from the inverse or the reciprocal of the standing wave ratio, that is, the ratio of the antinodal and nodal amplitudes

AEOLIAN VIBRATION DAMPERS FOR SINGLE CONDUCTORS

-

IEEE Std 664-1980

I O 0

5

3

2

v, t k a 3 z 10.0

3 a

(r W

0

5

3

2

I

VIBRATION DAMPER POWER DISSIPATION DAMPER AT 107 mm SPACING CONDUCTOR DIAMETER STRANDS'

3 4 mm ( I I92 5 kcmi l ) (GRACKLE)

NUMBER 7 3 ALUMINUM 5 4 STEEL 19 DIAMETER 3 76 mm 2 2 6 mm MASS

RTS 191 kN (43100 I b ) TEST SPAN 23 3 m LENGTH

TENSION

2 2 8 k g / m ( I 5 2 6 I b / f t )

TEST 38 I kN ( 2 0 % RTS)

9

IEEE Std 664-1980 IEEE GUIDE ON THE MEASUREMENT O F THE PERFORMANCE OF

The damper dissipation is determined from (Eq 2) . Since the standing wave ratio is measur- ed in the loop adjacent t o the damper there is no requirement with this method to measure Pc. To make this guide as self-supporting as possible, a complete list of symbols and units is given in Appendix B.

The methods outlined give best results when the test span contains many loops but not less than three. The free loop antinodal and nodal amplitudes measured should be the first and second ones, away from the damper respectively particularly for the standing wave method. It is to be preferred that the components of the anti- nodal and nodal signals other than the funda- mental frequency be filtered out.

5. Test Procedure

The inherent damping characteristics of the conductor without a damper should first be determined in accordance with the recom- mendations in IEEE Std 563-1978. The damper should then be installed at the spacing recom- mended by the damper supplier and the power dissipated by the conductor-damper system shall be determined by the power or standing wave methods. In the case of the latter, the amplitude of a vibration antinode in a free loop and of the adjacent nodal point along the con- ductor span towards the damper should be measured. A minimum of three measurements about these points should be made to establish the nodal and antinodal amplitudes and the accuracy and repeatability of these amplitudes. Determinations of antinode and node ampli- tudes need to be made only once at each tun-

able frequency and test amplitude. The test frequencies should be in accordance (see IEEE Std 563-1978] with measurements made at each tunable resonance of the span within the specified frequency range. It is suggested that the damper dissipation capacity and the bend- ing amplitude be measured at three double amplitudes of:

33 67 100 y = - f ' 7 ' 7

where f = frequency in Hz

and at the conductor tension, expressed as a percentage of conductor rated tensile strength (RTS), of 25% and if necessary at any other tension of interest. The maximum bending amplitude during these measurements should not exceed 0.25 mm peak-to-peak (10 mils). In addition to the foregoing, the peak-to-peak amplitude of the damper clamp should be measured at each test condition.

The results should be shown in graphical and tabular form, similar to those illustrated by Fig 1 and the specimen table of results. Where commercial devices are being evaluated, it is prudent to test several nominally identical pieces to assess variability. Lot sizes between 5 and 10 are normally adequate. When this is done, both mean and range of power dissipa- tion at frequency should be reported. The table should include bending amplitude, conductor diameter, wire size and damper amplitude, and the test temperature, as this may have a bearing on the damper performance.

10

AEOLIAN VIBRATION DAMPERS FOR SINGLE CONDUCTORS IEEE

Std 664-1980

Appendixes

(These Appendixes are not a part of IEEE Std 664-1980, IEEE Guide on the Measurement of the Performance of Aeolian Vibration Dampers for Single Conductors.)

Appendix A

Sample Test Results Vibration Damper Power Dissipation

Table of Results'

Damper: at 1.07 m spacing Conductor

diamet,er 34 mm (1192.5) (kcmil) (Grackle) strands:

number 7 3 diameter

mass 2.28 kg/m RTS 191 KN test span length 23.3 m test tension 38.1 KN test temperature 2O0C

Loop Frequency

Hz 12.24 12.24 12.24 15.80 15.80 15.80 18.49 18.49 18.49 23.40 23.40 23.40 25.10 25.10 25.10 29.30 29.30 29.30 32.10 32.10 32.10 35.20 35.20 35.20 38.40 38.40 38.40

length m

5.89 5.89 5.89 4.64 4.64 4.64 3.83 3.83 3.83 3.25 3.25 3.25 2.92 2.92 2.92 2.57 2.57 2.57 2.31 2.31 2.31 2.13 2.13 2.13 1.96 1.96 1.96

Y mm 3.56 5.78 8.89 2.79 4.70 7.00 2.29 3.17 5.70 1.90 3.30 4.80 1.78 2.92 4.40 1.65 2.54 3.80 1.40 2.28 3.40 1.27 2.16 3.20 1.14 1.90 2.90

Aluminum 54 Steel 1 9 mm 3.76 mm 2.26 (1.526 Ibift) ( 4 3 100 Ib)

(20% RTS)

Bending Power Watts Damper x Gross Damper Amplitude Yd Amplitude D PT

0.21 2.24 0.34 5.56 0.52 9.93 0.16 3.76 0.27 7.82 0.41 14.47 0.14 4.20 0.23 10.96 0.34 18.90 0.11 5.09 0.19 11.46 0.28 25.10

0.10 4.56 0.17 9.78 0.26 20.62 0.10 5.00 0.15 9.02 0.22 24.00 0.08 6.46 0.13 12.55 0.20 20.48 0.07 6.05 0.13 12.13 01 9 23.40 0.07 6.26 0.1 1 14.80 0.17 25.13

pd 2.14 5.34 7.79 3.50 7.37

11.36 4.04

10.40 15.20

4.87 10.50 20.83

4.26 8.72

16.13 4.65 8.05

20.02 6.10

11.43 16.55

5.53 11.61 19.60

5.74 14.30 21.20

mm 2.79 6.10 9.14 1.27 2.67 4.06 1.78 4.19 6.35 1.02 1.78 2.54 0.51 0.76 1.52 1.27 2.29 3.68 1.52 2.92 4.83 1.78 3.43 5.08 1.65 3.56 5.59

mm 0.09 0.17 0.25 0.05 0.08 0.11 0.08 0.10 0.15 0.05 0.06 0.1 0 0.03 0.03 0.03 0.06 0.09 0.15 0.06 0.10 0.1 5 0.05 0.13 0.20 0.08 0.15 0.23

- ~

'Performed by Ontario Hydro.

(1.0 (1 .0 (1.0

(2.0 (3.5 (6.0 (2 .5 (4 .0 (6 .0

11

IEEE Std 664-1980

Appendix B

List of Symbols

P = power dissipated by conductor per unit length

conductor span and terminations

PT = power dissipated by damper and conductor

Pd = power dissipated by damper

Pmax = maximum theoretical power that can be dissipated by damper

Pc = power dissipated by

T = tension 1 = loop length y = single amplitude at

antinode

milliwatts/ meter

watts

watts

watts

watts

newtons meter millimeters

Y = double amplitude a t antinode

V = transverse velocity at antinode - single amplitude

a,

f = frequency m = mass per unit length of

conductor D = diameter of conductor F = single amplitude

exciting force RTS = rated tensile strength L = free length of span yd = double amplitude a t

the damper clamp

= double amplitude at nth node

millimeters

meters per second

millimeters

hertz kglmeter

millimeters newtons

kilonewtons meters millimeters

Appendix C

Additional Notes on Power Method

C1. Due to the nonlinear characteristics of tend to enhance the apparent effectiveness of dampers in general, it may not always be pos- some dampers. sible to produce a sinusoidal velocity signal a t c2. Over resonance. Ideally the components in the signal, other than the fundamental, should be filtered

frequency rallges it may not be possible to resonate the damper-conductor system due to the high inertia force developed

out but normally they are not sufficiently large to cause a significant error in computing the power dissipation Of the damper* The general effect Of these components be to reduce

by Some dampers. For this situation, the power dissipated by the system will be the force times the conductor velocity, a t the point of the ap- plication of the exciting force, times the cosine

the energy input from the wind and therefore of the phase-angle between them.

12