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

CISPR 18-2:2010(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. The frequency range covered is 0,15 MHz to 300 MHz. A general procedure for establishing the limits of the radio noise field from the power lines and equipment is recommended, together with typical values as examples, and methods of measurement. The clause on limits concentrates on the low frequency and medium frequency bands and it is only in these bands where ample evidence, based on established practice, is available. No examples of limits to protect radio reception in the frequency band 30 MHz to 300 MHz have been given, as measuring methods and certain other aspects of the problems in this band have not yet been fully resolved. Site measurements and service experience have shown that levels of noise from power lines at frequencies higher than 300 MHz are so low that interference is unlikely to be caused to television reception. The values of limits given as examples are calculated to provide a reasonable degree of protection to the reception of broadcasting at the boundary of the recognized service areas of the appropriate transmitters in the radio frequency bands used for a.m. broadcasting, in the least favourable conditions likely to be generally encountered. These limits are intended to provide guidance at the planning stage of the line and national standards or other specifications against which the performance of the line may be checked after construction and during its useful life. The measuring apparatus and methods used for checking compliance with limits should comply with the respective CISPR specifications, as e.g. the basic standards series CISPR 16. 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 18-2 only considered the direct distance D0 for the establishment of standard profiles for the lateral radio noise field emanating from HV overhead power lines,
- this second edition now also allows for use of the lateral distance y0 for these purposes. This way it allows for conduction of on-site measurements and simplified recording and use of measurement data obtained at lateral distances y slant to the pathway of modern HV and UHV overhead power line constructions with tall suspension towers.

General Information

• Status: Published
• Publication Date: 23-Jun-2010
• ICS: 33.100.01 - Electromagnetic compatibility in general
• Technical Committee: CIS/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
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 27-Oct-2017

Relations

• Revised: CISPR TR 18-2:2017 - Radio interference characteristics of overhead power lines and high-voltage equipment - Part 2: Methods of measurement and procedure for determining limits
• Effective Date: 05-Sep-2023

Standards Content (Sample)

TR CISPR 18-2
®
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 2: Methods of measurement and procedure for determining limits


TR CISPR 18-2:2010(E)

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TR CISPR 18-2
®
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 2: Methods of measurement and procedure for determining limits


INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XB
ICS 33.100.01 ISBN 978-2-88912-017-8
® Registered trademark of the International Electrotechnical Commission

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– 2 – TR CISPR 18-2 © IEC:2010(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8
1 Scope.10
2 Normative references .10
3 Terms and definitions .11
4 Measurements.11
4.1 Measuring instruments .11
4.1.1 Response of a standard quasi-peak CISPR measuring receiver to a.c.
generated corona noise .11
4.1.2 Other measuring instruments.12
4.2 On-site measurements on HV overhead power lines.12
4.2.1 General .12
4.2.2 Measurements in the frequency range from 0,15 MHz to 30 MHz.12
4.2.3 Measurements in the frequency range from 30 MHz to 300 MHz.14
4.3 Statistical evaluation of the radio noise level of a line.15
4.4 Additional information to be given in the report.16
4.5 Measurements on HV equipment in the laboratory.16
4.5.1 Overview .16
4.5.2 State of the test object.17
4.5.3 Test area.17
4.5.4 Atmospheric conditions.18
4.5.5 Test circuit – Basic diagram.18
4.5.6 Practical arrangement of the test circuit.18
4.5.7 Test circuit components.19
4.5.8 Measuring receiver connections .19
4.5.9 Mounting and arrangement of test object .21
4.5.10 Measurement frequency .21
4.5.11 Checking of the test circuit .21
4.5.12 Calibration of the test circuit .21
4.5.13 Test procedure .22
4.5.14 Related observations during the test.23
4.5.15 Data to be given in test report .23
5 Methods for derivation of limits for HV power systems .24
5.1 Overview .24
5.2 Significance of CISPR limits for power lines .24
5.3 Technical considerations for derivation of limits for lines .25
5.3.1 Basic approach.25
5.3.2 Scope.25
5.3.3 Minimum broadcast signal levels to be protected .26
5.3.4 Required signal-to-noise ratio.27
5.3.5 Use of data on radio noise compiled during measurements in the
field .28
5.3.6 Use of data obtained by prediction of the radio noise from high-
voltage overhead power lines .29
5.4 Methods of determining compliance of measured data with limits .30
5.4.1 Long-term recording .30
5.4.2 Sampling method.31

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TR CISPR 18-2 © IEC:2010(E) – 3 –
5.4.3 Survey methods.31
5.4.4 Alternative criteria for an acceptable noise level .31
5.5 Examples for derivation of limits in the frequency range below 30 MHz .32
5.5.1 Radio reception .32
5.5.2 Television reception, 47 MHz to 230 MHz .33
5.6 Additional remarks .34
5.7 Technical considerations for derivation of limits for line equipment and
HVAC substations .34
5.7.1 General .34
5.7.2 Current injected by line components and hardware.35
5.7.3 Current injected by substation equipment .35
5.7.4 Practical derivation of limits in the l.f. and m.f. band .35
6 Methods for derivation of limits for the radio noise produced by insulator sets .37
6.1 General considerations.37
6.2 Insulator types.37
6.3 Influence of insulator surface conditions.38
6.3.1 General .38
6.3.2 Clean insulators .38
6.3.3 Slightly polluted insulators.38
6.3.4 Polluted insulators .39
6.4 Criteria for setting up radio noise limits for insulators .39
6.4.1 General .39
6.4.2 Criterion for insulators to be installed in type A areas .40
6.4.3 Criterion for insulators to be installed in type B areas .40
6.4.4 Criterion for insulators to be installed in type C areas .40
6.5 Recommendations.40
7 Methods for derivation of limits for the radio noise due to HVDC converter stations
and similar installations .42
7.1 General considerations.42
7.2 Sources of interference .43
7.2.1 Mechanism of radio noise generation .43
7.2.2 Influence of station design on radio interference.43
7.3 Radiated fields from valve halls .44
7.3.1 Frequency spectra.44
7.3.2 Lateral attenuation.44
7.3.3 Reduction of the radio interference due to direct radiation from the
valve hall.44
7.4 Conducted interference along the transmission lines .45
7.4.1 Description of the mechanism and typical longitudinal profiles.45
7.4.2 Reduction of the interference conducted along the transmission lines.45
7.5 General criteria for stating limits.46
7.5.1 Overview .46
7.5.2 Direct radiation .46
7.5.3 Propagation along the lines .46
8 Figures .48
Annex A (informative) Radio interference measuring apparatus differing from the
CISPR basic standard instruments.62
Annex B (normative) List of additional information to be included in the report on the
results of measurements on operational lines .63

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– 4 – TR CISPR 18-2 © IEC:2010(E)
Annex C (informative) Minimum broadcast signal levels to be protected – ITU
recommendations .64
Annex D (informative) Minimum broadcast signals to be protected – North American
standards.65
Annex E (informative) Required signal-to-noise ratios for satisfactory reception.66
Annex F (informative) Derivation of the formula for the protected distance.69
Bibliography.70

Figure 1 – Transformation of pulses through a CISPR measuring receiver .48
Figure 2 – Bursts of corona pulses generated by alternating voltage.49
Figure 3 – Example of extrapolation to determine the radio noise field strength
reference level of a power line, here at the direct reference distance of 20 m .49
Figure 4 – Basic test circuit.50
Figure 5 – Standard test circuit .50
Figure 6 – Connection to the measuring receiver by a coaxial cable .51
Figure 7 – Connection to the measuring receiver by a balanced cable .51
Figure 8 – Special test circuit.51
Figure 9 – Arrangement for calibration of the standard test circuit.52
Figure 10 – Map showing boundaries of zones A, B, and C in regions 1 and 3 .53
Figure 11 – Illustration of the four basic parameters for a power transmission line .54
Figure 12 – Example of typical statistical yearly "all-weather" distributions of the radio-
noise levels of a bipolar direct current line (-----) and for an alternating current line in a
moderate climate (- - -) .55
Figure 13 – Example of radio noise voltage level V, as a function of the relative air
humidity R.H., in clean conditions and slightly polluted conditions, of a standard
insulator (-----) and a particular type of "low noise" insulator (- - -) .56
Figure 14 – Example of frequency spectra of pulses with different rise times, simulating
commutation phenomena in mercury valves and in thyristor valves.56
Figure 15 – Example of frequency spectra of the radio interference recorded outside
the hall of a mercury arc valve converter station with and without toroidal filters .57
Figure 16 – Example of frequency spectra of the radio interference recorded outside
the hall of a thyristor valve converter station for different operating conditions.57
Figure 17 – Attenuation of the field strength as a function of the distance on a
horizontal plane, for different frequencies .58
Figure 18 – Example of frequency spectrum of the radio interference in the vicinity of
a d.c. line (30 m) at a short distance from the converter station .59
Figure 19 – Example of frequency spectrum of the radio interference in the vicinity of
an a.c. line (20 m) at a short distance from the converter station .60
Figure 20 – Frequency spectra of radio interference at 20 m from the electrode line at
1,5 km from the Gotland HVDC link in Sweden with mercury arc groups or thyristor
groups in operation .60
Figure 21 – Frequency spectra of radio interference at 20 m from the electrode line at
1,5 km and 4,5 km from the Gotland HVDC link in Sweden with mercury arc groups in
operation .61
Figure 22 – Frequency spectra of the radio interference recorded along a 200 kV d.c.
line, at 20 m from the conductor, at different distances from the converter station .61

Table 1 – Number of n sets of measurement of the radio noise level and
corresponding values for factor k .16

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TR CISPR 18-2 © IEC:2010(E) – 5 –
Table 2 – Minimum usable broadcast signal field strengths in the v.h.f bands
according to CCIR .27
Table 3 – Recommendations for the radio noise voltage limits and for the test methods
for insulator sets installed in different areas.42
Table C.1 – Minimum field strength.64
Table C.2 – Nominal usable field strength.64
Table D.1 – Signal levels at the edge of the service area in North America .65
Table E.1 – Summary of signal-to-noise ratios for corona from a.c. lines (Signal
measured with average detector, noise measured with quasi-peak detector).66
Table E.2 – Quality of radio reception or degree of annoyance due to RFI .67

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– 6 – TR CISPR 18-2 © IEC:2010(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
____________

RADIO INTERFERENCE CHARACTERISTICS
OF OVERHEAD POWER LINES
AND HIGH-VOLTAGE EQUIPMENT –

Part 2: Methods of measurement
and procedure for determining limits


FOREWORD
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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 18-2, 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.

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TR CISPR 18-2 © IEC:2010(E) – 7 –
This edition includes the following significant technical changes with respect to the previous
edition: while the first edition of CISPR 18-2 only considered the direct distance D for the
0
establishment of standard profiles for the lateral radio noise field emanating from HV
overhead power lines, this second edition now also allows for use of the lateral distance y for
0
these purposes. This way it allows for conduction of on-site measurements and simplified
recording and use of measurement data obtained at lateral distances y slant to the pathway of
modern HV and UHV overhead power line constructions with tall suspension towers.
The text of this technical report is based on the following documents:
DTR Report on voting
CISPR/B/494/DTR CISPR/B/502/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.

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– 8 – TR CISPR 18-2 © IEC:2010(E)
INTRODUCTION
This technical report forms the second 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 conduction of on-site measurements of
electromagnetic noise fields in the vicinity of high-voltage (HV) overhead power lines and
substations and for determination of limits for protection of radio reception.
The recommendations given in this part 2 of the CISPR 18 series are intended to be a useful
aid to engineers involved in maintenance of overhead lines and substations 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 18-3 eventually contains
a Code of Practice for minimizing the generation of radio noise.
This second edition of CISPR/TR 18-2 was adapted to the modern structure and content of
technical reports issued by IEC. The first edition of CISPR 18-2 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 historical CISPR Rec. No. 56 given
below:
RECOMMENDATION No. 56

METHODS OF MEASUREMENT OF RADIO INTERFERENCE CAUSED BY
OVERHEAD POWER LINES AND HIGH-VOLTAGE EQUIPMENT AND
THE PROCEDURE FOR DETERMINING LIMITS

The CISPR
CONSIDERING
a) that a general description of the radio interference characteristics of overhead power lines
and high-voltage equipment has been published in CISPR 18-1,
b) that the methods of measurement of these characteristics need to be established,
c) that national authorities require guidance on the procedure for determining limits of such
radio interference.
RECOMMENDS
That the latest edition of CISPR/TR 18-2, including amendments, be used for methods of
measurement of radio interference characteristics of overhead power lines and high-voltage
equipment and for procedures for determining limits.
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.

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TR CISPR 18-2 © IEC:2010(E) – 9 –
The methods of measurement in CISPR/TR 18-2 detail the techniques and procedures for use
when measuring fields on site near to an overhead line and also the techniques and
procedures for making laboratory measurements of interference voltages and currents
generated by line equipment and accessories.
The procedures for determining limits define the expected values of radio noise field and the
width of the "disturbed" corridor following the route of the line.
This corridor takes into account the effective field strength of the wanted signal, the signal-to-
noise ratio selected and the expected strength of the noise field for a given line.
The procedures are only valid for long and medium waves as the procedures applicable to
VHF frequency-modulation broadcasting have not yet been decided, due to insufficient
knowledge.
It is emphasized that this part of CISPR 18 does not specify a single set of limits to be applied
internationally. Rather it details the procedures to enable national authorities to specify limits
where it is decided there is a need for regulations.

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