CISPR TR 18-3:2010
(Main)Radio interference characteristics of overhead power lines and high-voltage equipment - Part 3: Code of practice for minimizing the generation of radio noise
Radio interference characteristics of overhead power lines and high-voltage equipment - Part 3: Code of practice for minimizing the generation of radio noise
CISPR 18-3:2010(E), which is a technical report, applies to radio noise from overhead power lines and high-voltage equipment which may cause interference to radio reception, excluding the fields from power line carrier signals. The frequency range covered is 0,15 MHz to 300 MHz. This second edition cancels and replaces the first edition published in 1986. It is a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- while the first edition of CISPR 18-3 only covered recommendations for minimizing the generation of radio noise emanating from high-voltage (HV) power systems,
- this second edition now also covers a new clause providing formulae for predetermination of the radio noise field strength levels from HV overhead power lines with large conductor bundles.
Furthermore, Annex A was accomplished with a collation of predetermination formulae developed and used by several institutions around the world. The tables also contain typical examples of radio noise field strength levels obtained during some measurements campaigns at several HV overhead power line constructions.
General Information
Relations
Standards Content (Sample)
TR CISPR 18-3
®
Edition 2.0 2010-06
TECHNICAL
REPORT
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Radio interference characteristics of overhead power lines and high-voltage
equipment –
Part 3: Code of practice for minimizing the generation of radio noise
TR CISPR 18-3:2010(E)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2010 IEC, Geneva, Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.
IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: inmail@iec.ch
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
---------------------- Page: 2 ----------------------
TR CISPR 18-3
®
Edition 2.0 2010-06
TECHNICAL
REPORT
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Radio interference characteristics of overhead power lines and high-voltage
equipment –
Part 3: Code of practice for minimizing the generation of radio noise
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
X
ICS 33.100.01 ISBN 978-2-88912-018-5
® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – TR CISPR 18-3 © IEC:2010(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.8
2 Normative references .8
3 Terms and definitions .8
4 Practical design of overhead power lines and associated equipment in order to
control interference to radio broadcast sound and television reception .8
4.1 Overview .8
4.2 Corona on conductors .9
4.3 Corona on metal hardware .9
4.4 Surface discharges on insulators.9
4.4.1 Clean or slightly polluted insulators .9
4.4.2 Very polluted insulators .10
4.5 Spark and microsparks due to bad contacts, commutation effects .10
4.6 Defects on power lines and associated equipment in service.10
5 Methods of prediction of the reference level of an overhead line.11
5.1 General .11
5.2 Correlation of data given elsewhere in this publication .11
5.3 CIGRÉ formula .12
5.4 Determination of 80 % level.13
5.5 Conclusions .13
6 Preventive and remedial measures to minimize radio noise generated by bad
contacts and their detection and location.14
6.1 General .14
6.2 Preventive and remedial measures.14
6.3 Methods of detecting and locating bad contacts .15
7 Formulae for predetermination of the radio noise field strength produced by large
conductor bundles (more than four sub-conductors) and by tubular conductors .17
7.1 Basic principles .17
7.2 Calculation of corona radio noise field strengths due to large bundles .18
7.2.1 Procedure for the predetermination of the radio noise field strength .18
7.2.2 Calculation of the excitation function in heavy rain .18
7.2.3 Correction factor to evaluate the excitation function in other weather
categories .19
7.2.4 Calculation of the radio noise field strength .19
7.3 Evaluation of corona radio noise field strength due to large tubular
conductors .20
8 Figures .22
Annex A (informative) Formulae for predicting the radio noise field strength from the
conductors of an overhead line .30
Annex B (informative) Analytical procedure for the predetermination of the radio noise
field strength, at a given distance from an overhead line with large bundle conductors .38
Bibliography.45
Figure 1 – Bundle conductors .22
Figure 2 – Line with conductors in a flat configuration.23
---------------------- Page: 4 ----------------------
TR CISPR 18-3 © IEC:2010(E) – 3 –
Figure 3 – Line with conductors in a delta configuration .24
Figure 4 – Line with conductors in a triangular configuration .25
Figure 5 – Line with conductors in a flat configuration.26
Figure 6 – Line with conductors in a delta configuration .27
Figure 7 – Line with conductors in a triangular configuration .28
Figure 8 – Tubular conductors of 40 cm diameter .29
Figure B.1 – Designation of the geometrical quantities for the simplified analytical
method .43
Figure B.2 – Lateral profiles of the radio noise field strengths produced by the
individual phases and of the total field, as calculated in the given example.44
Table A.1 – Empirical methods, terms of the predetermination formulae developed by
several institutions, survey.32
Table A.2 – Empirical methods, complete predetermination formulae developed by
several institutions, survey.34
Table A.3 – Predetermination formulae, examples for calculation of the absolute field
strength levels .36
---------------------- Page: 5 ----------------------
– 4 – TR CISPR 18-3 © IEC:2010(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
____________
RADIO INTERFERENCE CHARACTERISTICS
OF OVERHEAD POWER LINES
AND HIGH-VOLTAGE EQUIPMENT –
Part 3: Code of practice for minimizing
the generation of radio noise
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
CISPR 18-3, which is a technical report, has been prepared by CISPR subcommittee B:
Interference relating to industrial, scientific and medical radio-frequency apparatus, to other
(heavy) industrial equipment, to overhead power lines, to high voltage equipment and to
electric traction.
This second edition cancels and replaces the first edition published in 1986. It is a technical
revision.
---------------------- Page: 6 ----------------------
TR CISPR 18-3 © IEC:2010(E) – 5 –
This edition includes the following significant technical changes with respect to the previous
edition: while the first edition of CISPR 18-3 only covered recommendations for minimizing the
generation of radio noise emanating from high-voltage (HV) power systems, this second
edition now also covers a new clause providing formulae for predetermination of the radio
noise field strength levels from HV overhead power lines with large conductor bundles.
Furthermore, Annex A was accomplished with a collation of predetermination formulae
developed and used by several institutions around the world. The tables also contain typical
examples of radio noise field strength levels obtained during some measurements campaigns
at several HV overhead power line constructions.
The text of this technical report is based on the following documents:
DTR Report on voting
CISPR/B/495/DTR CISPR/B/503/RVC
Full information on the voting for the approval of this technical report can be found in the
report on voting indicated in the above table.
This technical report has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the CISPR 18 series can be found, under the general title Radio
interference characteristics of overhead power lines and high-voltage equipment, on the IEC
website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
---------------------- Page: 7 ----------------------
– 6 – TR CISPR 18-3 © IEC:2010(E)
INTRODUCTION
This technical report forms the third of a three-part publication dealing with radio noise
generated by electrical power transmission and distribution facilities (overhead lines and
substations). It contains recommendations for minimizing the generation of radio noise
emanating from high-voltage (HV) power systems which include, but are not restricted to,
HVAC or HVDC overhead power lines, HVAC substations and HVDC converter stations,
hardware, etc., in order to promoting protection of radio reception.
The recommendations given in this part 3 of the CISPR 18 series are intended to be a useful
aid to engineers involved in design, erection and maintenance of overhead lines and HV
stations and also to anyone concerned with checking the radio noise performance of a line to
ensure satisfactory protection of radio reception. Information on the physical phenomena
involved in the generation of electromagnetic noise fields is found in CISPR/TR 18-1. It also
includes the main properties of such fields and their numerical values. CISPR/TR 18-2
contains recommendations for methods of measurement for use on-site or in a laboratory. It
furthermore recommends procedures for determination of limits for the radio noise from HV
power systems.
This second edition of CISPR 18-3 was adapted to the modern structure and content of
technical reports issued by IEC. The first edition of CISPR 18-3 underwent thorough edition
and adaptation to modern terminology. Furthermore its content was adjusted such as to allow
for use of the lateral distance y for the conduction of measurements in the field.
The CISPR 18 series does not deal with biological effects on living matter or any issues
related to exposure in electromagnetic fields.
The main content of this technical report is based on CISPR Rec. No. 57 given below:
CISPR RECOMMENDATION No. 57
CODE OF PRACTICE FOR MINIMIZING THE GENERATION OF RADIO NOISE
The CISPR
CONSIDERING
a) that the radiation of electromagnetic energy from overhead power lines causes
interference to sound and television broadcasting,
b) that the level of this noise may be reduced by the design and lay-out of a line,
c) that when defects cause unusually high levels of interference there is need to detect and
locate these faults,
RECOMMENDS
That the latest edition of CISPR Publication 18-3, including amendments, be used as guide
for minimizing the generation of radio noise caused by overhead power lines.
CISPR/TR 18-1 describes the main properties of the physical phenomena involved in the
production of disturbing electromagnetic fields by overhead lines and provides numerical
values of such fields.
In CISPR/TR 18-2 methods of measurement and procedures for determining limits of such
radio interference are recommended.
This CISPR/TR 18-3 forms a "Code of Practice" to reduce to a minimum the production of
radio noise by power lines and equipment.
---------------------- Page: 8 ----------------------
TR CISPR 18-3 © IEC:2010(E) – 7 –
It provides information which is advisable to follow both when designing various fittings and
components and when stringing the conductors and installing the hardware of the line.
It also describes methods of detecting and locating defects resulting in unusually high
interference levels, and provides prevention and correction procedures that are generally
simple to implement.
Lastly, this Part 3 provides formulae for predicting the most probable radio noise field of a line
for various weather conditions, insofar as radio noise is caused by conductor corona.
---------------------- Page: 9 ----------------------
– 8 – TR CISPR 18-3 © IEC:2010(E)
RADIO INTERFERENCE CHARACTERISTICS
OF OVERHEAD POWER LINES
AND HIGH-VOLTAGE EQUIPMENT –
Part 3: Code of practice for minimizing
the generation of radio noise
1 Scope
This part of CISPR 18, which is a technical report, applies to radio noise from overhead power
lines and high-voltage equipment which may cause interference to radio reception, excluding
the fields from power line carrier signals.
The frequency range covered is 0,15 MHz to 300 MHz.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-161, International Electrotechnical Vocabulary (IEV) – Chapter 161:
Electromagnetic compatibility
CISPR/TR 18-1:2010, Radio interference characteristics of overhead power lines and high-
voltage equipment – Part 1: Description of phenomena
CISPR/TR 18-2:2010, Radio interference characteristics of overhead power lines and high-
voltage equipment – Part 2: Methods of measurement and procedure for determining limits
ISO/IEC Guide 99, International vocabulary of metrology – Basic and general concepts and
associated terms (VIM)
NOTE Informative references are listed in the Bibliography.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the IEC 60050-161 and
the ISO/IEC Guide 99 apply.
4 Practical design of overhead power lines and associated equipment
in order to control interference to radio broadcast sound and television
reception
4.1 Overview
This clause provides guidance on the techniques that may be applied during the design,
construction and operation of high voltage overhead power lines and associated equipment in
order to keep the various types of radio noise described in this publication within acceptable
levels.
---------------------- Page: 10 ----------------------
TR CISPR 18-3 © IEC:2010(E) – 9 –
4.2 Corona on conductors
During line design, consideration should be given to the geometric parameters of the line, in
order to ensure that radio noise due to conductor corona will not exceed a specified
acceptable level. The most important parameters are conductor diameter and number of
conductors per phase. Others that could be varied, such as distance between phases, height
of conductors above ground or spacing of sub-conductors in the bundle, have a smaller effect.
In practice they are usually determined by mechanical or insulation requirements.
The quantitative laws that determine the level of radio noise caused by conductor corona are
discussed in 4.3 of CISPR/TR 18-1, and in Clause 7 below. These laws normally apply to both
stranded and smooth conductors, since the surface unevenness caused by stranding does not,
in general, substantially change the noise level, especially when conductors are damp or wet.
The existence of scratched or broken strands or deposits of extraneous substances such as
dirt or insects on the surface, on the other hand, may lead to severe localised corona
discharges, due to high local voltage gradients. This may considerably increase the noise
level of the line. For these reasons it is necessary to avoid damage to the conductor surface
during construction. It should be handled with great care in transportation and erection and
suitable techniques should be used to avoid contact of the conductor with the ground or other
objects during stringing. It is also advisable to avoid external greasing of the conductor for
protection during transportation and tensioning; when the conductor is loaded, the increase in
temperature, especially in hot weather, will cause this grease to run to the outside, gathering
dirt and leading to areas with high local gradient and consequent radio noise. When the steel
core or inside layers are greased for corrosion protection, a type of grease should be selected
that will not migrate to the surface of the conductor even at the highest temperature.
4.3 Corona on metal hardware
Radio noise due to corona on metal hardware, such as suspension clamps, dead-end clamps,
yokes, guard rings, horns, spacers, etc., can be controlled. Appropriate shapes and
dimensions may be specified during the design stage in order to avoid points of high voltage
gradient. All edges and corners should be well rounded, bolt heads should be rounded or
shielded and sharp points and protrusions should be avoided. It is also important that the
protective galvanized finish on hardware be smooth, particularly at points of maximum voltage
gradient.
Guard devices are sometimes installed to protect an insulator string from the destructive
effects of a power arc and to improve the distribution of the potential along the string. They
also contribute to the reduction of the level of radio noise from the conductor clamps, since
they screen sharp points or protrusions on the clamps. The type and dimensions of the guard
devices should be chosen in such a way that they do not themselves produce radio noise. For
example, the use of simple horns should be avoided at voltages exceeding about 150 kV, and
the diameter of tubes forming guard rings should be sufficiently large to ensure that no corona
occurs during rain.
Present knowledge seems to indicate, however, that it may be relatively difficult to design
guard rings suitable for rainy conditions, even if they are made of multiple tubes. In which
case, it may be necessary to devise special arrangements for the yoke so that the string is
screened directly by the conductor bundle and is protected from power arcs by suitable
devices on the sub-conductors of the bundle.
As in the case of conductors, it is important to avoid damage to the hardware during
manufacture, transportation, construction and maintenance by handling them with great care
at all times.
4.4 Surface discharges on insulators
4.4.1 Clean or slightly polluted insulators
The radio noise produced by these insulators under dry conditions can be controlled by:
---------------------- Page: 11 ----------------------
– 10 – TR CISPR 18-3 © IEC:2010(E)
– the use of insulators of suitable design, especially as regards their geometry and the
characteristics of the material at the more critical areas, or
– the use of guard devices designed to improve the distribution of voltage on the surface of
the insulator or along the insulator string.
In insulator design, the use of conducting glaze, for example, improves the distribution of the
surface voltage gradient on the insulator. In the design of a guard device, a metal ring as
close as possible to the insulator, or to at least the first two or three insulators at the line end
of an insulator string, may considerably improve the voltage distribution on the insulator or
along the insulator string and reduce radio noise. The ring, however, shall remain compatible
with other requirements such as insulation withstand, protection of the insulators from power
arcs, screening of the clamps, etc. (see 4.3).
The radio noise produced in damp weather, fog or rain is usually more difficult to control than
the noise under dry conditions. It is, however, seldom a critical factor in line design, since the
increase in noise due to water droplets on the insulators is usually less important than the
corresponding increase in noise produced by the conductors.
4.4.2 Very polluted insulators
Under dry conditions, in addition to the phenomena that cause noise on a clean insulator,
other phenomena of the corona type may occur due to surface unevenness created by
pollution deposits, as mentioned in 6.1 of CISPR/TR 18-1. Under these conditions even
careful design of the various parts of an insulator may be of little benefit. Stress control
devices suitable for improving the voltage distribution on the insulator or along the insulator
string, however, may considerably improve the radio noise performance.
When the polluted insulator surface is wet, radio noise is generated by sparks across the dry
bands, created by the leakage currents, as discussed in 6.1 of CISPR/TR 18-1. Occasionally,
this noise has very high frequency components. It may affect both sound and television
reception and is difficult to control. The only practical remedy is to limit the leakage current
activity on the surface of the polluted insulator. This may be achieved by:
a) diminishing the voltage stress on the insulator – for example by using a longer surface
creepage path than is necessary for electrical withstand;
b) using special types of insulators such as those made of organic material or coated with
semi-conducting glaze, or designs with a longer creepage path such as fog type units,
special shapes, etc.;
c) coating the insulators with silicone grease.
4.5 Spark and microsparks due to bad contacts, commutation effects
Remedial measures for eliminating or reducing these types of radio noise are described in
Clause 5 below and in 8.4 of CISPR/TR 18-1 respectively.
4.6 Defects on power lines and associated equipment in service
Even if all possible precautions have been taken during design and construction of a power
line or substation to keep radio noise within acceptable limits, defects may occasionally occur
during operation, resulting in intolerable noise. This may be caused by breakage of strands on
the conductors, damage to clamps or insulators or accumulation of pollution on conductors
and insulators. In general, these defects shall be eliminated in order that the power system
may operate properly, whether or not they are sources of radio noise. In fact, the occasional
noise caused by such defects may result in detection and location of potential power system
faults.
These abnormal noise sources may be located by various instruments such as radio noise
measuring sets, television receivers or ultrasonic and optic
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.