IEC PAS 62344:2007

PUBLICLY
IEC
AVAILABLE
PAS 62344
SPECIFICATION
First edition
Pre-Standard
2007-05
General guidelines for the design
of ground electrodes for high-voltage
direct current (HVDC) links
Reference number
IEC/PAS 62344:2007(E)
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PUBLICLY
IEC
AVAILABLE
PAS 62344
SPECIFICATION
First edition
Pre-Standard
2007-05
General guidelines for the design
of ground electrodes for high-voltage
direct current (HVDC) links
PRICE CODE
Commission Electrotechnique Internationale X

International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – PAS 62344 © IEC:2007(E)
CONTENTS
FOREWORD .4
INTRODUCTION .5
1 Scope. 6
2 Basic concepts .6
2.1 Monopolar system .6
2.2 Bipolar system .7
2.3 Mixed or combined systems .8
3 Electric field as the decisive factor for selection of site.9
3.1 Why is the electric field the decisive factor? .9
3.2 Data necessary to determine the field.9
3.2.1 Reference currents (or electrode rating).9
3.2.2 Resistivity data .9
3.3 Considerations on site selection .9
3.4 Calculation of field.10
3.5 Apparent resistivity.11
4 Impact of the field on buried metallic objects .11
4.1 Impact on non-insulated buried metallic objects .11
4.2 Impact on insulated metallic objects .12
4.3 Impact on an a.c. grid .12
4.4 Reduction of impact due to polarization .14
4.4.1 Polarization on non-insulated metallic objects .14
4.4.2 Polarization on insulated metallic objects .16
4.4.3 Reduction of star-point currents due to polarization .16
5 Compass errors.17
6 Types of electrode stations .17
7 Design aspects for land electrodes .18
7.1 General .18
7.2 Heating of soil .19
7.3 Moisture content of soil/electric osmosis .20
7.4 Material for land electrodes.20
7.4.1 Inner conductor .20
7.4.2 Coke or graphite powder filling .21
7.5 Geometric layout of the electrode .22
7.5.1 Horizontal arrangements.22
7.5.2 Vertical arrangements.24
7.6 Step voltage.24
7.7 Touch voltage .25
8 Design aspects for sea electrodes .25
8.1 General .25
8.2 Sea electrodes using titanium as active part (anodic operation).26
8.2.1 Material.26
8.2.2 Current density and gradients.26
8.2.3 Geometric layout .26
8.3 Sea electrodes using coke or SiFeCr-rods as active parts (reversible operation) .27
8.3.1 Overheating risk .27
8.3.2 Material for sea electrodes .27

PAS 62344 © IEC:2007(E) – 3 –
8.3.3 Geometric layout of reversible sea electrodes .28
8.4 Sea electrodes using bare copper conductors as active parts (cathodic
operation only) .28
9 Design aspects for shore electrodes .30
9.1 General .30
9.2 Beach electrode stations.30
9.3 Pond electrode stations .32
10 Chemical aspects .34
11 Connection converter station – Electrode station .35
11.1 Separation of a.c. grid from electrode station .35
11.2 Constructional principles of electrode connection .36
11.3 Detection of faults on electrode connections .36
11.4 Electrode connection terminations.37
12 Operating experience – Reliability, availability, maintainability.37
13 Commissioning.38
14 List of references.39
Appendix 1 .41
Appendix 2 .42
Appendix 3 .43
Appendix 4 .44
Appendix 5 .47

– 4 – PAS 62344 © IEC:2007(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
GENERAL GUIDELINES FOR THE DESIGN OF GROUND ELECTRODES
FOR HIGH-VOLTAGE DIRECT CURRENT (HVDC) LINKS

FOREWORD
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A PAS is a technical specification not fulfilling the requirements for a standard but made available
to the public.
IEC-PAS 62344 was submitted by the CIGRÉ (International Council on Large Electric
Systems) and has been processed by subcommittee 22F: Power electronics for electrical
transmission and distribution systems, of IEC technical committee 22: Power electronic
systems and equipment.
The text of this PAS is based on the This PAS was approved for publication by
following document: the P-members of the committee
concerned as indicated in the following
document:
Draft PAS Report on voting
22F/116/NP 22F/128/RVN
Following publication of this PAS, which is a pre-standard publication, the technical co
...