IEC TR 62672:2018

IEC TR 62672 ®
Edition 1.0 2018-09
TECHNICAL
REPORT
Reliability and availability evaluation of HVDC systems

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.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
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 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 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. 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: sales@iec.ch.
IEC TR 62672 ®
Edition 1.0 2018-09
TECHNICAL
REPORT
Reliability and availability evaluation of HVDC systems

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01 ISBN 978-2-8322-6065-4

– 2 – IEC TR 62672:2018  IEC 2018
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, abbreviated terms and symbols . 7
3.1 Outage terms . 8
3.2 Capacity terms . 8
3.3 Outage duration terms . 9
3.4 Time categories . 9
3.5 Availability and utilization terms . 10
3.6 Commutation failure performance terms . 11
3.7 Abbreviated terms and symbols . 11
4 Classification of HVDC transmission system equipment . 12
4.1 General . 12
4.2 AC and auxiliary equipment (AC-E) . 13
4.2.1 General . 13
4.2.2 AC filter and other reactive power equipment (AC-E.F) . 13
4.2.3 AC control and protection (AC-E.CP) . 13
4.2.4 Converter/interface transformer (AC-E.TX) . 13
4.2.5 Synchronous compensator (AC-E.SC) . 13
4.2.6 Auxiliary equipment and auxiliary power (AC-E.AX) . 14
4.2.7 Other AC switchyard equipment (AC-E.SW) . 14
4.3 Valves (V) . 14
4.3.1 General . 14
4.3.2 Valve electrical (V.E) . 14
4.3.3 Valve cooling (V.VC) . 14
4.3.4 Valve capacitor (V.C) . 14
4.3.5 Phase reactor (V.PR) . 14
4.4 DC control and protection equipment (C-P) . 14
4.4.1 General . 14
4.4.2 Local control and protection (C-P.L) . 15
4.4.3 Master control and protection (C-P.M) . 15
4.4.4 Telecommunication equipment (C-P.T) . 15
4.5 Primary DC equipment (DC-E) . 15
4.5.1 General . 15
4.5.2 DC filters (DC-E.F) . 15
4.5.3 DC smoothing reactors (DC-E.SR) . 15
4.5.4 DC switching equipment (DC-E.SW) . 15
4.5.5 DC measuring equipment (DC-E.ME) . 16
4.5.6 DC earth electrode (DC-E.GE) . 16
4.5.7 DC earth electrode line (DC-E.EL) . 16
4.5.8 Other DC switchyard and valve hall equipment (DC-E.O) . 16
4.6 Other (O) . 16
4.7 DC transmission line (TL). 16
4.7.1 General . 16
4.7.2 DC overhead transmission line (TL-OH) . 16
4.7.3 DC underground/submarine cable (TL-C) . 17

4.8 External (EXT) . 17
5 Classification and severity of fault events and restoration codes . 17
5.1 Classification of fault events . 17
5.2 Severity codes . 18
5.3 Restoration codes . 19
6 Instructions for compilation of report . 19
6.1 General . 19
6.2 General instructions . 19
6.3 Instructions for Table 2 and Table 3 . 20
6.3.1 Section 1 . 20
6.3.2 Section 2 . 20
6.3.3 Sections 3, 4 and 5 . 20
6.3.4 Section 6 . 21
6.3.5 Section 7 . 21
6.4 Instructions for Table 4 and Table 5 . 24
6.4.1 Forced outages – Table 4 . 24
6.4.2 Scheduled outages – Table 5 . 24
6.5 Instructions for Table 6 . 26
6.6 Instructions for Table 7 . 27
6.7 Instructions for Table 8 . 28
6.8 Instructions for Table 9 . 29
7 Interpretation and evaluation of reports . 29
7.1 Calculation of outage duration . 29
7.2 External events . 29
7.3 Protective operation . 30
7.4 Performance of special controls . 30
Annex A (informative) Outage log form and examples . 33
A.1 Example of an outage log . 33
A.2 Examples of application of rule f) of 6.3.3 – Scheduled outage during a
forced outage . 34
A.2.1 Case 1: Scheduled outage does not increase ODF or extends outage
duration . 34
A.2.2 Case 2: Scheduled outage increases ODF . 35
A.3 Examples of application of rule g) of 6.3.3 – Second outage during an
outage . 36
A.3.1 Case 1: Second outage does not increase ODF or extends outage
duration . 36
A.3.2 Case 2: Second outage extends duration . 37
A.3.3 Case 3: Second outage with variable ODF . 38
Annex B (informative) Sample annual report . 39
Bibliography . 45

Figure A.1 – Scheduled outage does not increase ODF or extends outage duration . 35
Figure A.2 – Scheduled outage increases ODF . 35
Figure A.3 – Second outage does not increase ODF or extends outage duration . 36
Figure A.4 – Second outage extends duration . 37
Figure A.5 – Second outage with variable ODF . 38

– 4 – IEC TR 62672:2018  IEC 2018
Table 1 – Classification of fault events . 18
Table 2 – DC system performance for back-to-back systems and for two-terminal
systems reporting jointly (corresponding to Table 1 of Cigré TB 590:2014) . 22
Table 3 – DC system performance for multi-terminal systems and for stations reporting
separately as part of two-terminal systems (corresponding to Table 1 M/S of Cigré TB
590:2014) .
...