IEC PAS 61169-35:2009

SLOVENSKI STANDARD
01-september-1998
Guide on methods of measurement of short duration transients on low voltage
power and signal lines
Guide on methods of measurement of short duration transients on low-voltage power
and signal lines
Guide sur les méthodes de mesure des transitoires de courte durée sur les lignes de
puissance et de contrôle basse tension
Ta slovenski standard je istoveten z: IEC/TS 60816
ICS:
29.240.01 2PUHåMD]DSUHQRVLQ Power transmission and
GLVWULEXFLMRHOHNWULþQHHQHUJLMH distribution networks in
QDVSORãQR general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

RAPPORT CEI
TECHNIQUE IEC
TECHNICAL
édition
Première
REPORT
First edition
Guide sur les méthodes de mesure des transitoires
de courte durée sur les lignes de puissance et de
contrôle basse tension
Guide on methods of measurement of short
duration transients on low voltage power and
signal lines
© CEI 1984 Droits de reproduction réservés — Copyright - all rights reserved
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— 3
816 © I E C 1984
CONTENTS
Page
FOREWORD
PREFACE
INTRODUCTION
Clause
1. Scope 7
2. Characteristics of transients 9
2.1 9
Environment-produced transients
2.2 Appliance-produced transients 9
2.3 Parameters to be measured 9
3.
Characteristics of mechanisms of coupling between transient sources and potentially
susceptible devices
3.1 Propagation modes 17
4. Susceptibility/Immunity 19
4.1 Damage effects 19
4.2 Malfunction effects 21
5. Instrumentation 23
5.1 Obtaining statistical data on parameters of transients
5.2 Transient counter 25
5.3 Peak voltmeter 25
5.4 Other parameters
5.5 Waveform recording and analysis
5.6 Transient energy measurements
5.7 Frequency domain measurement 39
5.8 Special inexpensive devices
Measurement techniques 6.
6.1 Measurement of conducted transients
6.2 Measurement of radiated transients
FIGURES
APPENDIX A — Method for measuring transient conducted emissions
APPENDIX B — Equipment input impedance
APPENDIX C — Example of a monitoring probe 89
Bibliography and references 90

1984 — 5 —
816 © IEC
INTERNATIONAL ELECTROTECHNICAL COMMISSION
GUIDE ON METHODS OF MEASUREMENT
OF SHORT DURATION TRANSIENTS
ON LOW VOLTAGE POWER AND SIGNAL LINES
FOREWORD
1) The formal decisions or agreements of the I EC on technical matters, prepared by Technical Committees on which all
the National Committees having a special interest therein are represented, express, as nearly as possible, an
international consensus of opinion on the subjects dealt with.
2) They have the form of recommendations for international use and they are accepted by the National Committees in
that sense.
In order to promote international unification, the IEC expresses the wish that all National Committees should adopt
3)
the text of the IEC recommendation for their national rules in so far as national conditions will permit. Any
divergence between the IEC recommendation and the corresponding national rules should, as far as possible, be
clearly indicated in the latter.
PREFACE
has been prepared by IEC Technical Committee No. 77: Electromagnetic
This report
Compatibility between Electrical Equipment including Networks.
The text of this repo rt is based on the following documents:
Six Months' Rule Report on Voting
77(CO)21
77(CO)20
Further information can be found in the Repo rt on Voting indicated in the table above.

— 7
816 © IEC 1984
GUIDE ON METHODS OF MEASUREMENT
OF SHORT DURATION TRANSIENTS
ON LOW VOLTAGE POWER AND SIGNAL LINES
INTRODUCTION
Transients appearing on power and signal lines are capable of producing a variety of effects
ranging from minor equipment performance degradation to catastrophic insulation breakdown.
They have a wide variety of waveforms, which depend upon the mechanism of generation.
Furthermore, those that originate from switching a.c. power on and off will have a form that
depends upon the exact moment in the power cycle at which switching takes place, but in
addition can have very complicated micro (detailed) and macro (overall) waveform
characteristics.
Because of this variety and the frequently random time of occurrence, there is considerable
difficulty in making a suitable measurement of a transient. The advent of new technologies in
device design and manufacture has increased concern for identifying more precisely the effects
of transients.
icular, a solid-state device can be susceptible even to an overvoltage of very sho rt
In part
(nanosecond) time duration. Furthermore, because of va riations in the waveforms, to have a
precise measurement of any given transient would require the measurement of a large number
of parameters. Even if one measures the exact waveform of a transient, for control purposes,
one must then describe the transient with a finite number of parameter values.
The choice of these parameters and their expected range of values is still a matter of some
speculation, and the proper method of measurement is still considered by some to be an open
question. Modern types of test equipment provide measurement capabilities not available
previously, but they must be used with particular care.
Accordingly, there is a need for well-defined and accepted methods of measuring transients
for two major reasons, namely so that:
a) measurements made by different laboratories may be compared;
b) meaningful limits may be placed on transients generated by particular types of equipment
and on the susceptibility of particular equipment to transients.
This guide has been prepared to assist in meeting these requirements. Note that in this
guide the concern is with transient phenomena which are not line-frequency related and are of
duration no greater than 40 ms. It is also not concerned with sustained voltage changes or
fluctuations.
1. Scope
rt duration
is intended to give guidance on methods of measurement of sho
This report
transients on low voltage power and signal lines.

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816 © I EC 1984
2. Characteristics of transients
Transients may be classified according to their origin as follows:
a) those produced by the environment, that is to say, by lightning;
those produced by electrical switching or faults;
b)
those produced internally within the circuits of particular equipment.
c)
2.1 Environment produced transients
These transients a rise from lightning and are most severe on overhead and unscreened
cable sections. At the point closest to the point at which the transient is generated, the
rise time can be sho rt and the amplitude high. The rise time and fall time can be
considerably lengthened and the amplitude reduced as the transient propagates along the
network. Typically, such transients have rise times of the order of microseconds and fall
times from 50 µs to 50 ms and may be oscillatory. The effects on inner conductors are
reduced in the case of screened cables and cables buried in areas of low ground
resistivity.
2.2 Appliance produced transients
Transients produced by appliances arise from three basic causes:
the operation of a mechanical or semiconductor switch;
a)
b) turn-on currents associated with the saturation properties of an iron-core transformer
or starting currents in motors;
c) faults within equipment.
The transient produced by a switch or fault can range from a simple surge or dip
(sag) to a very complex waveform caused by repeated "restriking" of an arc as the
contacts of a mechanical switch separate. The most serious transients usually arise as a
result of breaking an inductive circuit, for example, the blowing of a fuse. In many
cases, special techniques, such as placing capacitors across the contacts, will reduce the
magnitude of the transients generated, and in other cases suppression can be obtained by
the use of semiconductor devices. The transients can have rise times of the order of a
few nanoseconds in the immediate vicinity of the switch, that is to 'say, within a fraction
of a metre; however, at distances of several metres from the switch, the rise time will be
considerably increased due to attenuation of the line of the higher frequency components.
Switching of transformers produces transients which may be of the order of several times
the peak line voltage but will have rise times of the order of tens of microseconds.
Parameters to be measured
2.3
Because of the complex and variable nature of transients, it is difficult to specify
which parameters should be measured. Under such circumstances, it is useful to examine
the susceptibility characteristics of the equipment under consideration and to divide these
into several categories in order to determine the parameters to be measured (see Clause 4):
a) those which are susceptible to a restricted band of frequencies, such as radio or
carrier frequency receivers;
816 © I EC 1984 - 11 —
those which are susceptible to a broad band of low radio frequencies (for example, a
b)
mains rectifier). For such devices the peak voltage is usually the critical parameter;
but energy may also be an important parameter;
those which are susceptible to a broad band of frequencies in the higher frequency
c)
bands. The critical quantity is the rate of rise of the pulse. Digital equipment is often
susceptible to this parameter, and destruction of devices may also occur.
Some general measurement capabilities can be desirable but one may not be able to
measure all parameters with a single instrument. For convenience, these parameters may
be classified according to whether they give information in the time or frequency
domains.
Figure 1, page 62, illustrates the possible complex nature of a typical transient and
some of the time domain parameters that may be used to describe it. In addition,
effective pulse strength (voltage x time) and energy content may be significant.
The most common frequency domain parameter used to describe a transient is the
spectrum amplitude. The frequency vs. phase characteristic may also be impottant but is
not usually measured because of difficulties in both measurement and use of the data.
Where the interference is discontinuous in nature, time weighting techniques such as
those used in the C.I.S.P.R. instrument may also be applied. The unweighted component
is of interest in any case.
2.3.1 Relation between time domain and frequency domain parameters
Figure 2 a), page 63, shows a representative waveform of one type of transient
disturbance produced during a switching-off operation of a 220 V auxiliary conductor.
Figure 2 b), page 63, shows a spectrum amplitude representation of such a waveform.
The relationship between the spectrum amplitude plot and the time domain waveform is
best explained by comparing the relevant characteristics for a trapezoidal pulse.
The spectrum amplitude of a symmetrical trapezoidal pulse with the mean pulse time
T is, in the frequency range below f = 1/7t T, independent of frequency (this po rtion of
the spectrum amplitude curve is parallel to the abscissa) and has a magnitude equal to
the envelope of the
the amplitude-time area of the pulse. Above the frequency f = 1/n T
spectrum varies as 1/f. If the trapezoidal pulse has rise and fall times t, the envelope of
the spectrum amplitude above the frequency 1/1tt varies as 1/f2.
Note that on Figure 2 b) the abscissa is marked in megahertz on a logarithmic scale
6 uV
and the ordinate is given in decibels with respect to 1 µVs. (1 µVs corresponds to 10
in 1 MHz.) The spectrum amplitude representation can be calculated using standard
Fourier integral techniques. When the pulses are repeated at regular intervals, a discrete
spectrum rather than a continuous spectrum is obtained. In that case, a representation
corresponding to Figure 2 b) can be used, but the curve shown corresponds to the
amplitude of the discrete components (envelope curve) which are spaced on the
frequency scale at a distance corresponding to the repetition rate.

816 © I EC 1984 — 13 —
Accordingly, the following interpretation can be placed on Figure 2 b), page 63:
a) the low-frequency or flat po rtion of the curve is a level determined by the effective
area under the voltage-time curve shown in Figure 2 a), page 63;
b) the high-frequency po rtion, above about 20 MHz, falls off at a rate inversely
proportional to the square of the frequency, and the points at which this rate of
fall-off begins are determined by the rate of rise of the initial pa rt of the waveform
(that is to say to the amplitude U,);
c) the peak in the spectrum amplitude curve appears at a frequency equal to the
frequency of oscillation of the transient. Thus, if one is given a spectrum
rtant
corresponding to that in Figure 2 b), one can interpret it in terms of the impo
characteristics of the originating transient waveform.
Furthermore, as shown in Figure 2 b), at point p which is the point of intersection of
the actual curve with the low frequency (horizontal) po ion of the curve, by extending
rt
from this point a line with slope proportional to 1/f (shown dotted on Figure 2 b)) and
one with a slope proportional to 1/f 2 (the actual spectrum curve shown in the solid
line), one can obtain, from the scales shown on the right-hand po rtion of Figure 2 b) the
actual maximum voltage dB(V) and the rate of rise dB(kV/µs) [10]*.
Measuring practice sets limits on the viewing time in time domain measurements and
on bandwidth in frequency domain measurements. Therefore, if transients of unknown
characteristics (amplitude, rise time, duration, repetition f
...