IEC TS 62344:2022

Design of earth electrode stations for high-voltage direct current (HVDC) links - General guidelines

IEC TS 62344:2022 applies to the design of earth electrode stations for high-voltage direct current (HVDC) links. It is intended to provide necessary guidelines, limits, and precautions to be followed during the design of earth electrodes to ensure safety of personnel and earth electrodes, and reduce any significant impacts on DC power transmission systems and the surrounding environment. This edition includes the following significant technical changes with respect to the previous edition:
- Changed the requirement of earthing resistance limit for short-time unipolar earth system in 5.1.3.
- Corrected the coefficient before ρs from 0,015 9 to 0,008 in touch voltage limit calculation formula (3) in 5.1.5.
- Deleted the analytical calculation formulas of earthing resistance for sea and shore electrodes in 6.1.3.
- Changed the current density limit from 100 A/m2 to 40 A/m2 ~ 50 A/m2 for the sea electrodes that are not accessible to human beings or to marine fauna in 6.1.7.
- Extended some detailed technical requirements for the measurement of ground/water soil parameters in 6.2.5.
- Reformulated the types and characteristics of electrode element material for sea and shore electrodes in 6.3.2.
- Added an informative Annex B: Earth electrode design process.
- Added an informative Annex C: Test results of human body resistance.
- Deleted the formula for calculating the average soil resistivity using harmonic mean when processing the measurement data in D.2.6 of Annex D.
- Extended some detailed technical requirements of electrode online monitoring system in Annex H.
- CIGRE 675:2017 is added to the bibliography.
- Terminology and way of expressions are modified using more commonly used terms in the HVDC electrode design industries and English-speaking countries, so as to make the readers understand the content more easily.

General Information

• Status: Published
• Publication Date: 15-May-2022
• ICS: 29.240.99 - Other equipment related to power transmission and distribution networks
• Technical Committee: TC 115 - High Voltage Direct Current (HVDC) transmission for DC voltages above 100 kV
• Drafting Committee: MT 8 - TC 115/MT 8
• Current Stage: PPUB - Publication issued
• Start Date: 31-May-2022
• Completion Date: 16-May-2022

Relations

• Revises: IEC PAS 62344:2007 - General guidelines for the design of ground electrodes for high-voltage direct current (HVDC) links
• Effective Date: 05-Sep-2023
• Revises: IEC TS 62344:2013 - Design of earth electrode stations for high-voltage direct current (HVDC) links - General guidelines
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TS 62344 ®
Edition 2.0 2022-05
TECHNICAL
SPECIFICATION
colour
inside
Design of earth electrode stations for high-voltage direct current (HVDC) links –
General guidelines
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 Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
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
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IEC TS 62344 ®
Edition 2.0 2022-05
TECHNICAL
SPECIFICATION
colour
inside
Design of earth electrode stations for high-voltage direct current (HVDC) links –
General guidelines
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.99 ISBN 978-2-8322-1035-2
– 2 – IEC TS 62344:2022 © IEC 2022
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 12
3 Terms and definitions . 12
4 System conditions . 16
4.1 General principles . 16
4.2 System parameters related to earth electrode design . 16
4.2.1 Amplitude and duration of the current . 16
4.2.2 Polarity . 16
4.2.3 Designed lifespan . 16
4.2.4 Common earth electrodes . 17
5 Design of land electrode stations . 17
5.1 Main technical parameters . 17
5.1.1 General principles . 17
5.1.2 Temperature rise . 17
5.1.3 Earthing resistance . 17
5.1.4 Step voltage . 18
5.1.5 Touch voltage . 19
5.1.6 Current density . 19
5.1.7 Field intensity in fish ponds . 19
5.2 Electrode site selection and parameter measurement . 19
5.2.1 General principles . 19
5.2.2 Data collection survey . 20
5.2.3 Distance from converter station (substation) . 20
5.2.4 Environment conditions, terrain and landform . 20
5.2.5 Geophysical and geological surveys . 20
5.2.6 Topographical map . 20
5.2.7 Values selected during design . 20
5.3 Earth electrode and associated components . 21
5.3.1 General principles for material selection . 21
5.3.2 Selection of electrode elements and characteristics . 21
5.3.3 Chemical and physical properties of petroleum coke . 22
5.3.4 Current-guiding system . 22
5.3.5 Bus . 22
5.3.6 Electrode line and its monitoring device . 23
5.4 Electrode arrangement . 23
5.4.1 General principles . 23
5.4.2 Filling coke . 23
5.4.3 Selection of earth electrode shape . 23
5.4.4 Earth electrode corridor (right of way) . 24
5.4.5 Distance between sub-electrodes in the arrangement . 24
5.4.6 Burial depth of the earth electrodes . 24
5.4.7 Segmentation of earth electrodes . 25
5.5 Minimum size of earth electrode. 25
5.5.1 General principles . 25

5.5.2 Total earth electrode length . 25
5.5.3 Area of the surface of the coke-soil interface . 25
5.5.4 Diameter of electrode elements . 26
5.6 Current guiding system . 26
5.6.1 General principles . 26
5.6.2 Placement of the current-guiding wire . 26
5.6.3 Connection of current-guiding wire . 27
5.6.4 Selection of current-guiding wire cross-section . 27
5.6.5 Insulation of the current-guiding wire . 27
5.6.6 Disconnecting switch . 27
5.6.7 Connection of the feeding cable . 28
5.6.8 Connection of jumper cables . 28
5.6.9 Selection of cable structure . 28
5.6.10 Selection of cable cross-section . 28
5.6.11 Selection of cable insulation . 29
5.6.12 Cable welding position . 29
5.6.13 Welding . 29
5.6.14 Mechanical protection for cable . 29
5.7 Auxiliary facilities . 29
5.7.1 Online monitoring . 29
5.7.2 Moisture replenishment . 29
5.7.3 Exhaust equipment . 30
5.7.4 Fence . 30
5.7.5 Marker . 30
6 Design of sea electrode station and shore electrode station . 30
6.1 Main technical parameters . 30
6.1.1 General . 30
6.1.2 Temperature rise . 30
6.1.3 Earthing resistance . 30
6.1.4 Step voltage . 30
6.1.5 Touch voltage . 30
6.1.6 Voltage gradient in water . 30
6.1.7 Current density . 31
6.2 Electrode site selection and parameter measurement . 31
6.2.1 General principles . 31
6.2.2 Data collection survey . 31
6.2.3 Distance from converter station (substation) . 31
6.2.4 Environment conditions . 31
6.2.5 Measurement of ground/water parameters . 32
6.3 Earth electrode and associated components . 32
6.3.1 General principles for material selection . 32
6.3.2 Common electrode elements and characteristics . 32
6.3.3 Chemical properties of petroleum coke . 33
6.3.4 Current-guiding system . 33
6.3.5 Bus . 33
6.3.6 Electrode line monitoring device . 33
6.4 Electrode arrangement . 33
6.4.1 General principles . 33
6.4.2 Filling coke . 33

– 4 – IEC TS 62344:2022 © IEC 2022
6.4.3 Selection of earth electrode shape . 33
6.4.4 Segmentation of earth electrodes . 34
6.5 Current-guiding system . 34
6.5.1 Placement of the current-guiding wire . 34
6.5.2 Connection of current-guiding system .
...

IEC TS 62344 ®
Edition 2.0 2022-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Design of earth electrode stations for high-voltage direct current (HVDC) links –
General guidelines
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 Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 19 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc

If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC TS 62344 ®
Edition 2.0 2022-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Design of earth electrode stations for high-voltage direct current (HVDC) links –
General guidelines
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.99 ISBN 978-2-8322-1164-9

– 2 – IEC TS 62344:2022 RLV © IEC 2022
CONTENTS
FOREWORD . 9
INTRODUCTION . 2
1 Scope . 13
2 Normative references . 13
3 Terms and definitions . 13
4 System conditions . 17
4.1 General principles . 17
4.2 System parameters related to earth electrode design . 18
4.2.1 Amplitude and duration of the current . 18
4.2.2 Polarity . 18
4.2.3 Designed lifespan . 18
4.2.4 Common earth electrodes . 19
5 Design of land electrode stations . 19
5.1 Main technical parameters . 19
5.1.1 General principles . 19
5.1.2 Temperature rise . 19
5.1.3 Earthing resistance . 19
5.1.4 Step voltage . 20
5.1.5 Touch voltage . 21
5.1.6 Current density . 21
5.1.7 Field intensity in fish ponds . 21
5.2 Electrode site selection and parameter measurement . 22
5.2.1 General principles . 22
5.2.2 Data collection survey . 22
5.2.3 Distance from converter station (substation) . 22
5.2.4 Environment conditions, terrain and landform . 22
5.2.5 Terrain and landform .
5.2.6 Measurement of soil parameters .
5.2.7 Geological exploration .
5.2.5 Geophysical and geological surveys . 23
5.2.6 Topographical map . 23
5.2.7 Values selected during design . 23
5.3 Earth electrode and associated components . 24
5.3.1 General principles for material selection . 24
5.3.2 Selection of feeding rods electrode elements and characteristics. 24
5.3.3 Chemical and physical properties of petroleum coke . 25
5.3.4 Current-guiding system . 25
5.3.5 Bus . 25
5.3.6 Electrode line and its monitoring device . 25
5.4 Electrode arrangement . 25
5.4.1 General principles . 25
5.4.2 Filling coke . 26
5.4.3 Selection of earth electrode shape . 26
5.4.4 Earth electrode corridor (right of way) . 27
5.4.5 Distance between sub-electrodes in the arrangement . 27
5.4.6 Burial depth of the earth electrodes . 27

5.4.7 Segmentation of earth electrodes . 28
5.5 Minimum size of earth electrode. 28
5.5.1 General principles . 28
5.5.2 Total earth electrode length . 28
5.5.3 Side length of coke section Area of the surface of the coke-soil
interface . 28
5.5.4 Diameter of feeding rods electrode elements . 29
5.6 Current guiding system . 30
5.6.1 General principles . 30
5.6.2 Placement of the current-guiding wire . 30
5.6.3 Connection of current-guiding wire . 30
5.6.4 Selection of current-guiding wire cross-section . 31
5.6.5 Insulation of the current-guiding wire . 31
5.6.6 Disconnecting switch . 31
5.6.7 Connection of the feeding cable . 31
5.6.8 Connection of jumper cables . 32
5.6.9 Selection of cable structure . 32
5.6.10 Selection of cable cross-section . 33
5.6.11 Selection of cable insulation . 33
5.6.12 Cable welding position . 33
5.6.13 Welding . 33
5.6.14 Mechanical protection for cable . 33
5.7 Auxiliary facilities . 33
5.7.1 Online monitoring . 33
5.7.2 Soil treatment Moisture replenishment . 34
5.7.3 Exhaust equipment . 34
5.7.4 Fence . 34
5.7.5 Marker . 34
6 Design of sea electrode station and shore electrode station . 34
6.1 Main technical parameters . 34
6.1.1 General . 34
6.1.2 Temperature rise . 34
6.1.3 Earthing resistance . 34
6.1.4 Step voltage . 35
6.1.5 Touch voltage . 35
6.1.6 Voltage gradient in water . 36
6.1.7 Current density . 36
6.2 Electrode site selection and parameter measurement . 36
6.2.1 General principles . 36
6.2.2 Data collection survey . 36
6.2.3 Distance from converter station (substation) . 36
6.2.4 Environment conditions . 36
6.2.5 Measurement of soil parameters .
6.2.5 Measurement of ground/water parameters . 37
6.3 Earth electrode and associated components . 37
6.3.1 General principles for material selection . 37
6.3.2 Common feeding rods electrode elements and characteristics . 37
6.3.3 Chemical properties of petroleum coke . 38
6.3.4 Current-guiding system . 38

– 4 – IEC TS 62344:2022 RLV © IEC 2022
6.3.5 Bus . 38
6.3.6 Electrode line monitoring device . 38
6.4 Electrode arrangement . 38
6.4.1 General principles . 38
6.4.2 Filling coke .
...