SIST EN 61000-4-18:2007

SLOVENSKI STANDARD
01-september-2007
1DGRPHãþD
SIST EN 61000-4-12:1997
SIST EN 61000-4-12:1997/A1:2002
Elektromagnetna združljivost (EMC) - 4-18. del: Preskusne in merilne tehnike -
Preskus odpornosti proti nihanjemu valu (IEC 61000-4-18:2006)
Electromagnetic compatibility (EMC) -- Part 4-18: Testing and measurement techniques -
Oscillatory wave immunity test
Elektromagnetische Verträglichkeit (EMV) -- Teil 4-18: Prüf- und Messverfahren -
Prüfung der Störfestigkeit gegen schwingende Wellen
Compatibilité électromagnétique (CEM) -- Partie 4-18: Techniques d'essai et de mesure -
Essai d'immunité a l'onde oscillatoire amortie
Ta slovenski standard je istoveten z: EN 61000-4-18:2007
ICS:
33.100.20 Imunost Immunity
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61000-4-18
NORME EUROPÉENNE
April 2006
EUROPÄISCHE NORM
ICS 33.100.20 Partially supersedes EN 61000-4-12:1995 + A1:2001

English version
Electromagnetic compatibility (EMC) -
Part 4-18: Testing and measurement techniques -
Damped oscillatory wave immunity test
(IEC 61000-4-18:2006)
Compatibilité électromagnétique (CEM) -  Elektromagnetische Verträglichkeit (EMV) -
Partie 4-18: Techniques d'essai Teil 4-18: Prüf- und Messverfahren -
et de mesure - Prüfung der Störfestigkeit
Essai d'immunité gegen schwingende Wellen
à l'onde oscillatoire amortie (IEC 61000-4-18:2006)
(CEI 61000-4-18:2006)
This European Standard was approved by CENELEC on 2007-03-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61000-4-18:2007 E
- 2 - EN 61000-4-18:2007
Foreword
The text of document 77B/517/FDIS, future edition 1 of IEC 61000-4-18, prepared by SC 77B, High
frequency phenomena, of IEC TC 77, Electromagnetic compatibility, was submitted to the IEC-CENELEC
parallel vote and was approved by CENELEC as EN 61000-4-18 on 2007-03-01.
This European Standard deals with the immunity test against oscillatory waves which was formerly
covered by EN 61000-4-12:1995 + A1:2001, now superseded by EN 61000-4-12:2006. It constitutes a
technical revision by extending the frequency range.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2007-12-01
national standard or by endorsement
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-03-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61000-4-18:2006 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60694 NOTE Harmonized as EN 60694:1996 (not modified).
IEC 61000-2-9 NOTE Harmonized as EN 61000-2-9:1996 (not modified).
IEC 61000-2-10 NOTE Harmonized as EN 61000-2-10:1999 (not modified).
IEC 60068-1 NOTE Harmonized as EN 60068-1:1994 (not modified).
IEC 61000-4-25 NOTE Harmonized as EN 61000-4-25:2002 (not modified).
IEC 61010-1 NOTE Harmonized as EN 61010-1:2001 (not modified).
__________
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
1)
IEC 60050-161 - International Electrotechnical Vocabulary - -
(IEV) -
Chapter 161: Electromagnetic compatibility

1) 2)
IEC 61000-4-4 - Electromagnetic compatibility (EMC) - EN 61000-4-4 2004
Part 4-4: Testing and measurement
techniques - Electrical fast transient/burst
immunity test
1)
IEC 61000-6-6 - Electromagnetic compatibility (EMC) - -
-
Part 6-6: Generic standards - HEMP immunity
for indoor equipment
1)
Undated reference.
2)
Valid edition at date of issue.

NORME CEI
INTERNATIONALE
IEC
61000-4-18
INTERNATIONAL
Première édition
STANDARD
First edition
2006-11
PUBLICATION FONDAMENTALE EN CEM
BASIC EMC PUBLICATION
Compatibilité électromagnétique (CEM) –
Partie 4-18:
Techniques d’essai et de mesure –
Essai d’immunité à l’onde oscillatoire amortie

Electromagnetic compatibility (EMC) –
Part 4-18:
Testing and measurement techniques –
Damped oscillatory wave immunity test
© IEC 2006 Droits de reproduction réservés ⎯ Copyright - all rights reserved
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For price, see current catalogue

61000-4-18 © IEC:2006 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11

1 Scope and object.13
2 Normative references .13
3 Terms and definitions .15
4 General .17
4.1 Information on the slow damped oscillatory wave phenomenon .17
4.2 Information on the fast damped oscillatory wave phenomenon .19
5 Test levels.23
6 Test equipment.27
6.1 Generator.27
6.2 Specifications of the coupling/decoupling network .31
7 Test setup .35
7.1 Earthing connections.35
7.2 Ground reference plane.37
7.3 Equipment under test .37
7.4 Coupling/decoupling networks .39
7.5 Generators .39
8 Test procedure .39
8.1 Laboratory reference conditions .41
8.2 Execution of the test.41
9 Evaluation of test results .43
10 Test report.45

Annex A (informative) Information on test levels for the damped oscillatory wave .69

Bibliography.71

Figure 1 – Waveform of the damped oscillatory wave (open circuit voltage) .47
Figure 2 – Example of schematic circuit of the test generator for the damped oscillatory
wave.47
Figure 3 – Example of test setup for table-top equipment using the ground reference plane .49
Figure 4 – Example of test setup for floor-standing equipment using the ground
reference plane.49
Figure 5 – AC/DC power supply port, single phase, line-to-ground tests .51
Figure 6 – AC power supply port, three phases, line-to-ground test .53
Figure 7 – Input/output port, single circuit, line-to-ground test.55
Figure 8 – Input/output port, group of circuits with common return, line-to-ground test .57
Figure 9 – AC/DC power supply port, single phase, line-to-line test .59

61000-4-18 © IEC:2006 – 5 –
Figure 10 – AC power supply port, three phases, line-to-line test.61
Figure 11 – Input/output port, single circuit, line-to-line test .63
Figure 12 – Input/output port, group of circuits with common return, line-to-line test .65
Figure 13 – Test of a system with communication ports with fast operating signals
(generator output earthed) .67

Table 1 – Test levels for the slow damped oscillatory wave (100 kHz or 1 MHz) .25
Table 2 – Test levels for the fast damped oscillatory wave (3 MHz, 10 MHz or 30 MHz).25

61000-4-18 © IEC:2006 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-18: Testing and measurement techniques –
Damped oscillatory wave immunity test

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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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.
International Standard IEC 61000-4-18 has been prepared by subcommittee 77B: High
frequency phenomena, of IEC technical Committee 77: Electromagnetic compatibility.
It forms Part 4-18 of IEC 61000. It has the status of a basic EMC publication in accordance
with IEC Guide 107, Electromagnetic compatibility – Guide to the drafting of electromagnetic
compatibility publications.
This first edition of the standard cancels and replaces the content regarding damped
oscillatory waves in the first edition of IEC 61000-4-12, published in 1995, and its Amendment
1 (2000), and constitutes a technical revision by extending the frequency range.

61000-4-18 © IEC:2006 – 9 –
The text of this standard is based on the following documents:
FDIS Report on voting
77B/517/FDIS 77B/522/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
61000-4-18 © IEC:2006 – 11 –
INTRODUCTION
This standard is part of the IEC 61000 series, according to the following structure:
Part 1: General
General considerations (introduction, fundamental principles)
Definitions, terminology
Part 2: Environment
Description of the environment
Classification of the environment
Compatibility levels
Part 3: Limits
Emission limits
Immunity limits (in so far as they do not fall under the responsibility of the product
committees)
Part 4: Testing and measurement techniques
Testing techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic standards
Part 9: Miscellaneous
Each part is further subdivided into several parts, published either as international standards
or as technical specifications or technical reports, some of which have already been published
as sections. Others will be published with the part number followed by a dash and a second
number identifying the subdivision (example: 61000-6-1).
This part is an international standard which gives immunity requirements and test procedures
related to damped oscillatory waves.

61000-4-18 © IEC:2006 – 13 –
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-18: Testing and measurement techniques –
Damped oscillatory wave immunity test

1 Scope and object
This part of IEC 61000-4 relates to the immunity requirements and test methods for electrical
and electronic equipment, under operational conditions, with regard to:
a) repetitive damped oscillatory waves occurring mainly in power, control and signal cables
installed in high voltage and medium voltage (HV/MV) substations;
b) repetitive damped oscillatory waves occurring mainly in power, control and signal cables
installed in gas insulated substations (GIS) and in some cases also air insulated
substations (AIS) or in any installation due to HEMP phenomena.
The object of this basic standard is to establish the immunity requirements and a common
reference for evaluating in a laboratory the performance of electrical and electronic equipment
intended for residential, commercial and industrial applications, as well as of equipment
intended for power stations and substations, as applicable.
NOTE As described in IEC guide 107, this is a basic EMC publication for use by product committees of the IEC.
As also stated in Guide 107, the IEC product committees are responsible for determining whether this immunity
test standard should be applied or not, and if applied, they are responsible for determining the appropriate test
levels and performance criteria. TC 77 and its sub-committees are prepared to co-operate with product committees
in the evaluation of the value of particular immunity tests for their products.
The purpose of this standard is to define:
– test voltage and current waveforms;
– ranges of test levels;
– test equipment;
– test setup;
– test procedure.
The object of this standard is to establish a common reference for evaluating the immunity of
electrical and electronic equipment when subjected to damped oscillatory waves. The test
method documented in this part of IEC 61000 describes a consistent method to assess the
immunity of an equipment or system against a defined phenomenon.
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.

61000-4-18 © IEC:2006 – 15 –
lEC 60050(161): International Electrotechnical Vocabulary (IEV) – Chapter 161: Electro-
magnetic compatibility
IEC 61000-4-4: Electromagnetic compatibility (EMC) – Part 4-4: Testing and measurement
techniques – Electrical fast transient/burst immunity test
IEC 61000-6-6: Electromagnetic compatibility (EMC) – Part 6-6: Generic standards – HEMP
immunity for indoor equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions contained in lEC 60050-161,
some of which are repeated here for convenience, and the following terms and definitions
apply.
NOTE These terms are applicable to the restricted field of oscillatory transients.
3.1
air insulated substation
AIS
substation which is made up with only air insulated switchgear
3.2
burst
sequence of a limited number of distinct pulses or an oscillation of limited duration
[IEV 161-02-07]
3.3
calibration
set of operations which establishes, by reference to standards, the relationship which exists
under specified conditions, between an indication and a result of a measurement
NOTE 1 This term is based on the "uncertainty" approach.
NOTE 2 The relationship between the indications and the results of measurement can be expressed, in principle,
by a calibration diagram.
[IEV 311-01-09]
3.4
coupling
interaction between circuits, transferring energy from one circuit to another
3.5
coupling network
electrical circuit for the purpose of transferring energy from one circuit to another
3.6
decoupling network
electrical circuit for the purpose of preventing test voltages applied to the EUT (equipment
under test) from affecting other devices, equipment, or systems which are not under test
3.7
gas insulated (metal-enclosed) substation
GIS
substation which is made up with only gas insulated metal enclosed switchgear
[IEV 605-02-14]
61000-4-18 © IEC:2006 – 17 –
3.8
high-altitude electromagnetic pulse
electromagnetic pulse produced by a nuclear explosion outside the earth’s atmosphere
NOTE Typically above an altitude of 30 km
3.9
immunity (to a disturbance)
the ability of a device, equipment, or system to perform without degradation in the presence of
an electromagnetic disturbance
[IEV 161-01-20]
3.10
port
particular interface of the EUT with the external electromagnetic environment
3.11
rise time
interval of time between the instants at which the instantaneous value of a pulse first reaches
10 % value and then the 90 % value
[IEV 161-02-05, modified]
3.12
transient (adjective and noun)
pertaining to or designating a phenomenon or a quantity which varies between two
consecutive steady states during a time interval short compared with the time-scale of interest
[IEV 161-02-01]
3.13
verification
set of operations which is used to check the test equipment system (e.g. the test generator
and the interconnecting cables) and to demonstrate that the test system is functioning within
the specifications given in Clause 6
NOTE 1 The methods used for verification may be different from those used for calibration.
NOTE 2 The procedure of 6.1.3 and 6.2 is meant as a guide to insure the correct operation of the test generator,
and other items making up the test setup so that the intended waveform is delivered to the EUT.
[IEV 311-01-13, modified]
4 General
The damped oscillatory wave phenomena are divided into two parts. The first part is referred
to as the slow damped oscillatory wave and includes oscillation frequencies between 100 kHz
and 1 MHz. The second part is referred to as the fast damped oscillatory wave, and it includes
oscillation frequencies above 1 MHz. The causes of these two types of damped oscillatory
waves are described below.
4.1 Information on the slow damped oscillatory wave phenomenon
This phenomenon is representative of the switching of disconnectors in HV/MV open-air
substations, and is particularly related to the switching of HV busbars, as well as to the
background disturbance in industrial plants.

61000-4-18 © IEC:2006 – 19 –
In electrical stations, the opening and closing operations of HV disconnectors give rise to
sharp front-wave transients, with rise times of the order of some tens of nanoseconds.
The voltage front-wave has an evolution that includes reflections, due to the mismatching of
the characteristic impedance of HV circuits involved. In this respect, the resulting transient
voltage and current in HV busbars are characterized by a fundamental oscillation frequency
that depends on the length of the circuit and on the propagation time.
The oscillation frequency ranges from about 100 kHz to a few megahertz for open-air sub-
stations, depending on the influence of the parameters mentioned above and the length of the
busbars, which may vary from some tens of metres to hundreds of metres (400 m may occur).
In this respect, the oscillation frequency of 1 MHz may be considered representative of most
situations, but 100 kHz has been considered appropriate for large HV substations.
The repetition frequency is variable between a few hertz and a few kilohertz depending on the
distance between the switching contacts: that is, for close contacts, there is a maximum
repetition frequency, while for distances between the contacts near to the extinction of the
arc, the minimum repetition frequency, in respect of each phase, is twice the power frequency
(100/s per phase for 50 Hz and 120/s per phase for 60 Hz HV systems).
The repetition rates selected, 40/s and 400/s, represent therefore a compromise, taking into
account the different durations of the phenomena, the suitability of the different frequencies
considered and the problem related to the energy to which the circuits under test are
subjected.
In industrial plants, repetitive oscillatory transients may be generated by switching transients
and the injection of impulsive currents in power systems (networks and electrical equipment).
The systems have a local response in a frequency band well covered by the rise time and the
fundamental frequency of oscillation of the damped oscillatory wave selected for testing
purposes.
4.2 Information on the fast damped oscillatory wave phenomenon
The fast damped oscillatory wave immunity test should cover phenomena present in two
specific environments:
– substations of the power network (produced by switchgear and controlgear);
– all installations exposed to the high-altitude electromagnetic pulse (HEMP).
4.2.1 Disturbances produced by switchgear and controlgear
During opening or closing disconnector operations, between both contacts of the operated
device, a large number of restrikes take place due to the slow speed of the contacts.
Therefore, disconnector switch operations generate very fast transients, which propagate as
travelling waves in the busbars of the substation. The electrical length of the shielded
conductors and the length of the open circuit busbars determine the oscillation frequencies of
the transient overvoltages.
For air insulated substations (AIS) these transients will radiate an electromagnetic field in the
substation environment. Recent measurements have been performed in air insulated

61000-4-18 © IEC:2006 – 21 –
substations using instruments with a large frequency bandwidth [1]) . These measurements
have shown that transient phenomena with frequencies higher than 1 MHz can also take place
in these substations.
For gas insulated substations (GIS), these transients propagate inside the metallic enclosure,
which contains the SF gas. Due to the skin effect, high frequency transients are confined
inside the enclosure and cause no problems. At the enclosure discontinuities however, a part
of transients is transferred to the external surface of the enclosure tube. As a consequence,
the enclosure potential rises and the current flowing on the enclosure surface radiates an
electromagnetic field in the substation environment. The transient ground potential rise is a
direct source of transient common mode currents in the secondary circuits. The radiated
electromagnetic field also induces common mode currents in the secondary circuits.
Measurements have shown that the maximum frequency of significant components in the
spectral density of these currents can be as high as 30 MHz to 50 MHz (see Figures 1 and 2)
[2].
In Figures 1 and 2, it can be seen that several peaks occur in the current spectral density
characteristic and important spectral components are observed at frequencies of some tens of
MHz.
As summarized in [1], the frequency environment of HV substations (GIS, but also AIS) has
become more severe than it was in the past, due to a reduction in distances as a
consequence of the reduction of the overall sizes of substations, the use of gas insulated
substations (GIS) and the installation of electronic equipment nearer to switching devices.
Therefore, the oscillation frequencies of 3 MHz, 10 MHz and 30 MHz for the fast damped
oscillatory waves seem to be suitable to better take into account a more realistic environment
both in some AIS and in all GIS.
The repetition frequency is variable between a few hertz and many kilohertz depending on the
distance between the switching contacts: that is, with close contacts, there is a maximum
repetition frequency, while for distances between the contacts near to the extinction of the
arc, the minimum repetition frequency, in respect of each phase, is twice the power frequency
(100/s per phase for 50 Hz and 120/s per phase for 60 Hz HV systems).
The repetition rate selected, 5 000/s, is set to consider the higher repetition rates measured in
GIS. That rate still represents a compromise (as higher rates have been measured), taking
into account the different duration of the phenomena, the suitability of the different
frequencies considered and the problem related to the energy to which the circuits under test
are subjected.
4.2.2 Disturbances produced by the high-altitude electromagnetic pulse (HEMP)
The high-altitude electromagnetic pulse (HEMP) as presented in IEC 61000-2-9 [4] describes
an intense, plane wave electromagnetic pulsed field which has a rise time of 2,5 ns and a
pulse width of approximately 25 ns. This field interacts with exposed cables and wiring to
produce an oscillating voltage and current depending on the length of the line (see
IEC 61000-2-10 [5]). For most external lines such as power and communications, these lines
are long enough (often greater than 1 km) that the coupled currents and voltages are usually
impulsive in nature.
___________
1)
Figures in square brackets refer to the bibliography.

61000-4-18 © IEC:2006 – 23 –
For wires and cables inside of a building, the incident HEMP is partially attenuated, however,
there is still enough field present to couple to short cables inside, providing a threat to
connected electronic equipment. Experiments performed in the past clearly indicate that the
HEMP fields couple to these short lines and produce high-frequency damped oscillatory
waveforms with frequencies as high as 100 MHz, although frequencies below 30 MHz are the
most usual (see IEC 61000-2-10). The damping rate of the oscillatory wave is fairly rapid due
to the presence of absorbing walls in most buildings, and a resonance quality factor Q with a
value between 10 and 20 is therefore typical.
It is also noted that short external wiring, such as those found as part of control circuits in
power substations or at power plants are also likely to couple well to the HEMP fields. These
cables will also exhibit damped oscillatory voltages in the range of 1 to 100 MHz depending
on cable length.
Given that the HEMP environment is typically only one or two pulses, any test defined would
not necessarily require a high repetition rate to replicate the incident environment. However,
due to reliability concerns with digital electronics, it is recommended that a repetition rate
similar to that recommended for switchgear and controlgear also be applied for HEMP
(5 000/s) in order to increase the probability of discovering a malfunction. This is consistent
with the fact that protection and testing to HEMP are ordinarily only performed when the
consequences of electronic system failure are serious.
Concerning the HEMP immunity and generic standards that have been published to date
(IEC 61000-4-25 [7] and IEC 61000-6-6), there is a need to have a basic test standard for the
fast damped oscillatory wave containing information on test levels, the generator design, and
test procedures that will permit one to carry out the tests necessary for the levels of voltages
induced by a high-altitude electromagnetic pulse (HEMP). This voltage waveform is a fast
damped sine wave that stresses the connected equipment. Although many frequencies are
possible under realistic conditions, it has been decided that this fast oscillatory wave test
should be carried out with oscillation frequencies up to 30 MHz in order to provide
consistency with the environment produced in power network substations.
5 Test levels
The preferential range of test levels for the damped oscillatory wave tests, applicable to
power, signal and control ports of the equipment, is given in Tables 1 and 2. The test level is
defined as the voltage of the first peak (maximum or minimum) in the test waveform (Pk1 in
Figure 1).
Different levels may apply to power, signal and control ports. The level(s) used for signal and
control ports shall not differ by more than one level from that used for power supply ports.

61000-4-18 © IEC:2006 – 25 –
Table 1 – Test levels for the slow damped oscillatory wave (100 kHz or 1 MHz)
Level Common mode Differential mode
kV kV
1 0,5 0,25
2 1 0,5
a
3 1
4 - -
b
x x
x
a
The value is increased to 2,5 kV for substation equipment.
b
x can be any level, above, below or in-between the other levels. This level can be
given in the product standard.

Table 2 – Test levels for the fast damped oscillatory wave
(3 MHz, 10 MHz or 30 MHz)
Level Common mode
kV
1 0,5
2 1
3 2
4 4
a
x
x
a
x can be any level, above, below or in-between the
other levels. This level can be given in the product
standard.
The applicability of the damped oscillatory wave test shall refer to the product specification.
The test levels from Tables 1 and 2 should be selected on the basis of the exposure to the
primary phenomenon of the cables running in the installation. These levels are defined as an
open circuit voltage either at the output of the generator or at the output of the CDN used.
The immunity tests are correlated with these levels in order to establish a performance level
for the environment in which the equipment is expected to operate, taking into account the
primary phenomena and the installation practices which determine the classes of the
electromagnetic environment.
The installations to which this selection of the test levels is applicable are mainly the high-
voltage substations, as well as industrial plants provided with their own electrical plants
(transformer stations).
In HV electrical plants, the degree and length of parallelism of the cables with the busbars,
the operating voltage of these circuits, their shielding and earthing (grounding) will determine
the level of induced voltages.
In order to reduce as much as possible these variables, and taking into consideration that
equipment dedicated to this type of installation is used for a certain range of operating
voltages of the plants (for example, from 150 kV to 800 kV), the definition of the test level is
made considering mainly the equipment interconnected, its location, the quality of the cable
shielding, and its earthing (see Annex A).

61000-4-18 © IEC:2006 – 27 –
6 Test equipment
6.1 Generator
The generator output shall have the capability to operate under short-circuit conditions.
A block diagram of a representative damped oscillatory wave generator is shown in Figure 2.
The test generator produces a damped oscillatory wave with the following characteristics as it
shall be applied to the EUT port. If applied via a coupling/decoupling network, the
characteristics shall be as specified at the output of that network.
The generator output shall be floating and the stray capacity unbalance of the output
terminals to earth shall be less than 20 %. This condition is necessary to test EUT control and
signal ports in differential mode. A dual output generator is necessary. The fast generator
output has a single coaxial output. Test with this generator shall be made only in common
mode.
The provisions to be taken whenever the output of the generator is not floating are given in
item b) of 8.2.
The generator shall have provisions to prevent the emission of heavy disturbances that may
be injected in the power supply network, or may influence the test results.
6.1.1 Characteristics and performance of the slow damped oscillatory wave
generator
Specifications:
– voltage rise time (T1 in Figure 1): 75 ns ± 20 %;
– voltage oscillation frequencies (Note1): 100 kHz and 1 MHz ± 10 %;
– repetition rate: 40/s for 100 kHz and 400/s for 1 MHz ± 10 %;
– decaying: (See Figure 1) Pk5 must be > 50 % of the Pk1 value
and Pk10 must be < 50 % of the Pk1 value;
– burst duration: not less than 2 s;
– output impedance, Note 2: 200 Ω;
– open circuit voltage: (Pk1 value, 250 V to 2,5 kV ± 10 %;
See Figure 1)
– short-circuit current (Pk1 value): 1,25 A to 12,5 A ± 20 %;
– phase relationship with the power no requirement;
frequency
– polarity of the first half-period: positive and negative.

NOTE 1 Oscillation frequency is defined as the reciprocal of the period between the first and third zero crossings
after the initial peak. This period is shown as T in Figure 1.
NOTE 2 Output impedance is calculated as open circuit voltage Pk1 divided by short circuit current Pk1.
The waveform of the slow damped oscillatory wave with peak points marked, is given in
Figure 1.
An example of a schematic circuit of the generator is given in Figure 2.

61000-4-18 © IEC:2006 – 29 –
6.1.2 Characteristics and performance of the fast damped oscillatory wave generator
Specifications open circuit:
– voltage rise time (T1 in Figure 1): 5 ns ± 30 %;
– voltage oscillation frequencies (Note 1): 3 MHz, 10 MHz and 30 MHz ± 10 %;
– repetition rate: 5 000/s ± 10 %;
– decaying: (See Figure 1) Pk5 must be > 50 % of the Pk1 value
and Pk10 must be < 50 % of the Pk1 value;
– burst duration: 3 MHz: 50 ms ± 20 %
10 MHz: 15 ms ± 20%
30 MHz: 5 ms ± 20%
– burst period: 300 ms ± 20 %;
– output impedance (Note 2): 50 Ω ± 20 %;
– open circuit voltage: (Pk1 value, 250 V to 4 kV ± 10 %;
see Figure 1)
– phase relationship with the power no requirement;
frequency
– polarity of the first half-period: positive and negative.
Specifications short circuit:
– current rise time (T1 in Figure 1): 3 MHz: < 330 ns
10 MHz: < 100 ns
30 MHz: < 33 ns
– current oscillation frequencies (Note 1): 3 MHz, 10 MHz and 30 MHz ± 30 %;
– decaying: (See Figure 1) Pk5 must be > 25 % of the Pk1 value
and Pk10 must be < 25 % of the Pk1 value;
– short circuit current (Pk1 value): 5 A to 80 A ± 20 %.

NOTE 1 Oscillation frequency is defined as the reciprocal of the period between the first and third zero crossings
after the initial peak. This period is shown as T in Figure 1.
NOTE 2 Output impedance is calculated as open circuit voltage Pk1 divided by short circuit current Pk1.
The waveform of the fast damped oscillatory wave is given in Figure 1.
An example of a schematic circuit of the generator is given in Figure 2.
6.1.3 Impedance value
The output impedance of the slow generator has been fixed at 200 Ω although the actual
impedance of the cables (twisted pairs) is nearer to 150 Ω. The reason for which the 200 Ω
impedance has been selected is not to modify an existing general status that would involve
the technical specifications of a family of equipment, with applications mainly in high-voltage
substations.
The output impedance of the fast generator has been fixed at 50 Ω. The reason for which the
50 Ω impedance has been selected is to be consistent with the EFT/B generator as specified
in IEC 61000-4-4. 50 Ohm coaxial cable must be used to the CDN or coupler. To avoid
reflection the generator impedance must be 50 Ω.

61000-4-18 © IEC:2006 – 31 –
In addition, the cables in this category of electrical and industrial plants are mostly in the
order of hundreds of meters in length, and therefore the impedance of the connections in the
field is nearer the characteristic impedance of the cables, and not less than that value.
6.1.4 Verification of the characteristics of the test generator
The verification procedure is meant as a guide to insure the correct operation of the test
generator, coupling/decoupling networks, and other items making up the test setup so that the
intended waveform is delivered to the EUT.
In order to make it possible to compare the results of different test generators, the most
essential characteristics shall be verified.
The characteristics to be verified in accordance with the parameters of 6.1.1 and 6.1.2 are the
following:
– rise time;
– oscillation frequency;
– decaying;
– burst duration;
– burst period;
– open-circuit voltage (open circuit impedance: for slow generator Z ≥ 10 kΩ;
oc
– short circuit current (Pk1 value only by using a short circuit impedance: for slow and fast
generators Z ≤ 0,1 Ω);
sc
– generator source impedance.
The verifications shall be carried out with voltage or current probes (as applicable) and with
oscilloscopes or other equivalent measurement instrumentation with a minimum bandwidth of
40 MHz for the slow damped oscillatory waves and 400 MHz for the fast damped oscillatory
waves.
For the fast damped oscillatory waves generator:
– the open circuit test load impedance is 1 000 Ω ± 2 % in parallel with ≤ 6 pF. The
resistance measurement is made at d.c. and the capacitance measurement is made using
a commercially available capacitance meter that operates at low frequencies;
– the preferred device for measuring the short-circuit current is a shunt. Its transfer
impedance should be 0,1 Ω ± 2 %. The resistance verification of the shunt is made at d.c.
and the 3 dB bandwidth at 400 MHz can be verified with an appropriate network analyser.
NOTE  A short-circuit load impedance of Z = 0,102 Ω is considered as complying with the requirement of
sc
Z ≤ 0,1 Ω.
sc
The waveform characteristics shall be verified at the EUT port (port by port) of each CDN
used for the immunity test, or directly at the output of the test generator if no CDN is to be
used.
6.2 Specifications of the coupling/decoupling network
The coupling/decoupling network (CDN) provides both the ability to apply the test voltage in
either common (for both generators) or differential (only 100 kHz, 1 MHz) mode to the mains,
signal and control ports of the EUT (equipment under test), and prevents test voltage from
affecting any auxiliary equipment needed to perform the test. The waves shal
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