IEC TR 62681:2014

Electromagnetic performance of high voltage direct current (HVDC) overhead transmission lines

IEC TR 62681:2014 provides general guidance on the electromagnetic environment issues of HVDC transmission lines. It concerns the major parameters adopted to describe the electromagnetic environment of a High-Voltage Direct Current (HVDC) transmission line, including electric fields, ion current, magnetic fields radio interference, and audible noise generated as a consequence of such effects. Engineers in different countries can refer to this Technical Report to ensure the safe operation of HVDC transmission lines, limit the influence on the environment within acceptable ranges, and optimize engineering costs.

General Information

• Status: Published
• Publication Date: 11-Aug-2014
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: TC 115 - High Voltage Direct Current (HVDC) transmission for DC voltages above 100 kV
• Drafting Committee: WG 3 - TC 115/WG 3
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 25-May-2022

Relations

• Revised: IEC TR 62681:2022 - Electromagnetic performance of high voltage direct current (HVDC) overhead transmission lines
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TR 62681 ®
Edition 1.0 2014-08
TECHNICAL
REPORT
colour
inside
Electromagnetic performance of high voltage direct current (HVDC) overhead
transmission lines
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 Tel.: [phone]
3, rue de Varembé Fax: [phone]

CH-1211 Geneva 20 [e-mail]
Switzerland 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.

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IEC TR 62681 ®
Edition 1.0 2014-08
TECHNICAL
REPORT
colour
inside
Electromagnetic performance of high voltage direct current (HVDC) overhead

transmission lines
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XD
ICS 29.240.20 ISBN 978-2-8322-1780-1

– 2 – IEC TR 62681:2014  IEC 2014

CONTENTS
FOREWORD . 6

INTRODUCTION . 8

1 Scope . 9

2 Terms and definitions . 9

3 Electric field and ion current . 10

3.1 Description of the physical phenomena . 10

3.2 Calculation methods . 13
3.2.1 General . 13
3.2.2 Semi-analytic method . 14
3.2.3 Finite element method . 16
3.2.4 BPA method . 17
3.2.5 Empirical methods of EPRI . 18
3.2.6 Recent progress . 18
3.3 Experimental data . 19
3.3.1 General . 19
3.3.2 Instrumentation and measurement methods . 19
3.3.3 Experimental results for electric field and ion current . 21
3.3.4 Discussion . 21
3.4 Implication for human and natural environment . 22
3.4.1 General . 22
3.4.2 Static electric field . 23
3.4.3 Research on space charge . 23
3.4.4 Scientific review . 28
3.5 Design practice of different countries . 29
4 Magnetic field . 30
4.1 Description of physical phenomena . 30
4.2 Magnetic field of HVDC transmission lines . 31
5 Radio interference (radio noise) . 32
5.1 Description of radio interference phenomena of HVDC transmission system . 32
5.1.1 General . 32
5.1.2 Physical aspects of d.c. corona . 32
5.1.3 Mechanism of formation of a noise field of d.c. line . 33

5.1.4 Characteristics of radio interference from d.c. line . 33
5.1.5 Factors influencing the RI from d.c. line . 34
5.2 Calculation methods . 36
5.2.1 EPRI empirical formula . 36
5.2.2 IREQ empirical method . 37
5.2.3 CISPR bipolar line RI prediction formula . 38
5.2.4 Comparison of different prediction formula . 38
5.3 Experimental data . 38
5.3.1 Measurement apparatus and methods . 38
5.3.2 Experimental results for radio interference . 39
5.4 Criteria of different countries . 39
6 Audible noise . 40
6.1 Basic principles of audible noise . 40
6.2 Description of physical phenomena . 41

6.2.1 Lateral profiles . 42

6.2.2 Statistical distribution . 44

6.2.3 Influencing factors . 45

6.2.4 Effect of altitude above sea level . 47

6.2.5 Concluding remarks . 47

6.3 Calculation methods . 48

6.3.1 General . 48

6.3.2 Theoretical analysis of audible noise propagation . 48

6.3.3 Empirical formulas of audible noise . 49

6.3.4 Semi-empirical formulas of audible noise . 49

6.3.5 CEPRI (China) research results . 52
6.3.6 Concluding remarks . 52
6.4 Experimental data . 52
6.4.1 Measurement techniques and instrumentation . 52
6.4.2 Experimental results for audible noise . 53
6.5 Design practice of different countries . 53
6.5.1 General . 53
6.5.2 The effect of audible noise on people . 53
6.5.3 The audible noise level and induced complaints . 54
6.5.4 Limit values of audible noise of HVDC transmission lines in different
countries . 57
6.5.5 Recommended noise level limit . 58
6.5.6 Main conclusion . 58
Annex A (informative) Experimental results for electric field and ion current. 59
A.1 Bonneville Power Administration ±500 kV HVDC transmission line . 59
A.2 FURNAS ±600 kV HVDC transmission line . 59
A.3 Manitoba Hydro ±450 kV HVDC transmission line . 60
A.4 Hydro-Québec – New England ±450 kV HVDC transmission line . 62
A.5 IREQ test line study of ±450 kV HVDC line configuration . 63
A.6 HVTRC test line study of ±400 kV HVDC line configuration . 64
A.7 Test study in China . 66
Annex B (informative) Experimental results for radio interference . 68
B.1 Bonneville power administration’s 1 100 kV direct current test project . 68
B.1.1 General . 68
B.1.2 Lateral profile . 68

B.1.3 Influence of conductor gradient . 69
B.1.4 Percent cumulative distribution . 70
B.1.5 Influence of wind . 72
B.1.6 Spectrum . 72
B.2 Hydro-Québec institute of research . 74
B.2.1 General . 74
B.2.2 Cumulative distribution . 74
B.2.3 Spectrum . 75
B.2.4 Lateral profiles . 75
B.2.5 Cumulative distribution under different voltage . 76
B.3 d.c. line of China . 76
Annex C (informative) Experimental results for audible noise . 78
Bibliography . 81

– 4 – IEC TR 62681:2014  IEC 2014

Figure 1 – Unipolar and bipolar space charge regions of a HVDC transmission line [1] .
...

IEC TR 62681 ®
Edition 1.0 2014-08
TECHNICAL
REPORT
colour
inside
Electromagnetic performance of high voltage direct current (HVDC) overhead
transmission lines
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 Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland 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.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 14
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 55 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC TR 62681 ®
Edition 1.0 2014-08
TECHNICAL
REPORT
colour
inside
Electromagnetic performance of high voltage direct current (HVDC) overhead

transmission lines
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XD
ICS 29.240.20 ISBN 978-2-8322-1780-1

– 2 – IEC TR 62681:2014  IEC 2014
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Terms and definitions . 9
3 Electric field and ion current . 10
3.1 Description of the physical phenomena . 10
3.2 Calculation methods . 13
3.2.1 General . 13
3.2.2 Semi-analytic method . 14
3.2.3 Finite element method . 16
3.2.4 BPA method . 17
3.2.5 Empirical methods of EPRI . 18
3.2.6 Recent progress . 18
3.3 Experimental data . 19
3.3.1 General . 19
3.3.2 Instrumentation and measurement methods . 19
3.3.3 Experimental results for electric field and ion current . 21
3.3.4 Discussion . 21
3.4 Implication for human and natural environment . 22
3.4.1 General . 22
3.4.2 Static electric field . 23
3.4.3 Research on space charge . 23
3.4.4 Scientific review . 28
3.5 Design practice of different countries . 29
4 Magnetic field . 30
4.1 Description of physical phenomena . 30
4.2 Magnetic field of HVDC transmission lines . 31
5 Radio interference (radio noise) . 32
5.1 Description of radio interference phenomena of HVDC transmission system . 32
5.1.1 General . 32
5.1.2 Physical aspects of d.c. corona . 32
5.1.3 Mechanism of formation of a noise field of d.c. line . 33
5.1.4 Characteristics of radio interference from d.c. line . 33
5.1.5 Factors influencing the RI from d.c. line . 34
5.2 Calculation methods . 36
5.2.1 EPRI empirical formula . 36
5.2.2 IREQ empirical method . 37
5.2.3 CISPR bipolar line RI prediction formula . 38
5.2.4 Comparison of different prediction formula . 38
5.3 Experimental data . 38
5.3.1 Measurement apparatus and methods . 38
5.3.2 Experimental results for radio interference . 39
5.4 Criteria of different countries . 39
6 Audible noise . 40
6.1 Basic principles of audible noise . 40
6.2 Description of physical phenomena . 41

6.2.1 Lateral profiles . 42
6.2.2 Statistical distribution . 44
6.2.3 Influencing factors . 45
6.2.4 Effect of altitude above sea level . 47
6.2.5 Concluding remarks . 47
6.3 Calculation methods . 48
6.3.1 General . 48
6.3.2 Theoretical analysis of audible noise propagation . 48
6.3.3 Empirical formulas of audible noise . 49
6.3.4 Semi-empirical formulas of audible noise . 49
6.3.5 CEPRI (China) research results . 52
6.3.6 Concluding remarks . 52
6.4 Experimental data . 52
6.4.1 Measurement techniques and instrumentation . 52
6.4.2 Experimental results for audible noise . 53
6.5 Design practice of different countries . 53
6.5.1 General . 53
6.5.2 The effect of audible noise on people . 53
6.5.3 The audible noise level and induced complaints . 54
6.5.4 Limit values of audible noise of HVDC transmission lines in different
countries . 57
6.5.5 Recommended noise level limit . 58
6.5.6 Main conclusion . 58
Annex A (informative) Experimental results for electric field and ion current. 59
A.1 Bonneville Power Administration ±500 kV HVDC transmission line . 59
A.2 FURNAS ±600 kV HVDC transmission line . 59
A.3 Manitoba Hydro ±450 kV HVDC transmission line . 60
A.4 Hydro-Québec – New England ±450 kV HVDC transmission line . 62
A.5 IREQ test line study of ±450 kV HVDC line configuration . 63
A.6 HVTRC test line study of ±400 kV HVDC line configuration . 64
A.7 Test study in China . 66
Annex B (informative) Experimental results for radio interference . 68
B.1 Bonneville power administration’s 1 100 kV direct current test project . 68
B.1.1 General . 68
B.1.2 Lateral profile . 68
B.1.3 Influence of conductor gradient . 69
B.1.4 Percent cumulative distribution . 70
B.1.5 Influence of wind . 72
B.1.6 Spectrum . 72
B.2 Hydro-Québec institute of research . 74
B.2.1 General . 74
B.2.2 Cumulative distribution . 74
B.2.3 Spectrum . 75
B.2.4 Lateral profiles . 75
B.2.5 Cumulative distribution under different voltage . 76
B.3 d.c. line of China . 76
Annex C (informative) Experimental results for audible noise . 78
Bibliography . 81

– 4 – IEC TR 62681:2014  IEC 2014

Figure 1 – Unipolar and bipolar space charge regions of a HVDC transmission line [1] . 11
Figure 2 – Lateral profile of magnetic field on the ground of ±800 kV HVDC lines . 32
Figure 3 – The c
...