IEC TS 60071-5:2002

TECHNICAL IEC
SPECIFICATION TS 60071-5
First edition
2002-06
Insulation co-ordination –
Part 5:
Procedures for high-voltage direct
current (HVDC) converter stations

Coordination de l’isolement -
Partie 5:
Procédures pour les stations de conversion CCHT

Reference number
IEC/TS 60071-5:2002(E)
Publication numbering
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TECHNICAL IEC
SPECIFICATION TS 60071-5
First edition
2002-06
Insulation co-ordination –
Part 5:
Procedures for high-voltage direct
current (HVDC) converter stations

Coordination de l’isolement -
Partie 5:
Procédures pour les stations de conversion CCHT

© IEC 2002 ⎯ Copyright - all rights reserved
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 the publisher.
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– 2 – TS 60071-5  IEC:2002(E)
CONTENTS
FOREWORD.5
1 General .7
1.1 Scope.7
1.2 Additional background .7
2 Normative references.8
3 Definitions .8
4 Symbols and abbreviations .12
4.1 Subscripts .12
4.2 Letter symbols .12
4.3 Abbreviations.12
4.4 Typical HVDC converter station schemes and associated graphical symbols .13
5 Principles of insulation co-ordination .15
5.1 Essential differences between a.c. and d.c. systems .15
5.2 Insulation co-ordination procedure .16
6 Voltages and overvoltages in service .18
6.1 Arrangements of arresters .18
6.2 Continuous operating voltages at various locations in the converter station .19
6.3 Peak (PCOV) and crest value (CCOV) of continuous operating voltage
applied to valves and arresters .20
6.4 Sources and types of overvoltages.21
6.5 Overvoltage limiting characteristics of arresters .24
6.6 Valve protection strategy .25
6.7 Methods and tools for overvoltage and surge arrester characteristic studies .25
6.8 Necessary system details .28
7 Design objectives of insulation co-ordination .30
7.1 Arrester requirements .31
7.2 Characteristics of insulation .33
7.3 Representative overvoltages.33
7.4 Determination of the required withstand voltage .36
7.5 Determination of the specified withstand voltage .37
7.6 Creepage distances.37
7.7 Clearances in air .37
8 Creepage distances and clearances in air .37
8.1 Creepage distance for outdoor insulation under d.c. voltage.38
8.2 Creepage distance for indoor insulation under d.c. voltage .38
8.3 Creepage distance of a.c. insulators (external).38
8.4 Clearances in air .39
9 Arrester requirements .39
9.1 Arrester specification .39
9.2 AC bus arrester (A).40
9.3 AC filter arrester (FA) .40
9.4 Valve arrester (V) .40
9.5 Bridge arrester (B).42
9.6 Converter unit arrester (C) .43

TS 60071-5  IEC:2002(E) – 3 –
9.7 Mid-point d.c. bus arrester (M) .43
9.8 Converter unit d.c. bus arrester (CB).43
9.9 DC bus and d.c. line/cable arrester (DB and DL) .44
9.10 Neutral bus arrester (E) .44
9.11 DC reactor arrester (DR).45
9.12 DC filter arrester (FD) .45
9.13 Earth electrode station arrester.45
Annex A (informative) Example of insulation co-ordination for conventional HVDC
converters .46
Annex B (informative) Example of insulation co-ordination for Controlled Series
Capacitor Converters (CSCC) and Capacitor Commutated Converters (CCC).55
Annex C (informative) Considerations for insulation co-ordination of some special
converter configurations.69
Bibliography .75
Figure 1 – Single line diagram of typical converter pole with two 12-pulse
converters in series.13
Figure 2 – Single line diagram of typical capacitor commutated converter (CCC) pole
with two 12-pulse converters in series .14
Figure 3 – Single line diagram of typical controlled series compensated converter
(CSCC) pole with two 12-pulse converters in series .14
Figure 4 – HVDC converter station diagram with 12-pulse converter bridges .18
Figure 5 – Continuous operating voltages at various locations (location identification
according to figure 4) .20
Figure 6 – Operating voltage of a valve arrester (V), rectifier operation .21
Figure 7 – One pole of an HVDC converter station.29
Figure A.1 – AC and DC arresters (400 kV a.c. side for conventional HVDC converters) .52
Figure A.2 – Simplified circuit configuration for stresses of valve arrester at slow-front
overvoltages from a.c. side (conventional HVDC converters) – Illustration of
slow-front overvoltage wave (applied voltage).53
Figure A.3 – Stresses on valve arrester V2 at slow-front overvoltage from a.c. side
(conventional HVDC converter ) .53
Figure A.4 – Circuit configuration for stresses on valve arrester at earth fault on
transformer HV bushing (conventional HVDC converters) .54
Figure A.5 – Stresses on valve arrester V1 during earth fault on HV bushing of
converter transformer (conventional HVDC converter) .54
Figure B.1a – AC and DC arresters (400 kV a.c. side for CCC converters) .62
Figure B.1b – AC and DC arresters (400 kV a.c. side for CSCC converter) .63
Figure B.2a – Simplified circuit configuration for stresses on valve arrester at slow-front
overvoltages from a.c. side (CCC converter) .64
Figure B.2b – Simplified circuit configuration for stresses on valve arrester at slow-front
overvoltages from a.c. side (CSCC converter) .64
Figure B.3a – Stresses on valve arrester V2 at slow-front overvoltage from a.c. side
(CCC converter).65
Figure B.3b – Stresses on valve arrester V2 at slow-front overvoltage from a.c. side
(CSCC converter).65

– 4 – TS 60071-5  IEC:2002(E)
Figure B.4a – Circuit configuration for stresses on valve arrester at earth fault on HV
bushing of converter transformer (CCC converter).66
Figure B.4b – Circuit configuration for stresses on valve arrester at earth fault
on HV bushing of converter transformer (CSCC converter) .66
Figure B.5a – Stresses on valve arrester V1 during earth fault on HV bushing of
converter transformer (CCC converter).67
Figure B.5b – Stresses on valve arrester V1 during earth fault on HV bushing of
converter transformer (CSCC converter) .67
Figure B.6a – Stresses on CCC capacitor arrester Ccc during earth fault on HV bushing
of converter transformer (CCC converter).68
Figure B.6b – Stresses on CSCC capacitor arrester Csc during earth fault on HV
bushing of converter transformer (CSCC converter).68
Figure C.1 – Expanded HVDC converter with parallel valve groups .70
Figure C.2 – Upgraded HVDC converter with series valve group .72
Table 1 – Symbol description .14
Table 2 – Comparison of the selection
...