IEC TS 62672-1:2013

Reliability and availability evaluation of HVDC systems - Part 1: HVDC systems with line commutated converters

IEC/TS 62672-1:2013(E) applies to all line-commutated high-voltage direct current (HVDC) transmission systems used for power exchange in utility systems. HVDC stations with voltage sourced converters (VSC) are not covered. The purpose of this part of IEC 62672 is to define a standardized reporting protocol so that data collected from different HVDC transmission systems can be compared on an equitable basis. It covers point-to-point transmission systems, back-to-back interconnections and multi-terminal transmission systems. For point-to-point systems and back-to-back interconnections, i.e. two-terminal systems, statistics are to be reported based on the total transmission capability from the sending end to the receiving end measured at a given point. If, however, the two terminals are operated by different users/owners, or are composed of equipment of different vintage or of equipment from different suppliers, statistics can be reported on an individual station basis if so desired by those responsible for reporting. In such a case, the outage should only be reported under the originating converter station taking care not to report the same event twice. For distributed multi-terminal systems, i.e. systems with more than two terminals, statistics are to be reported separately for each converter station based on its own individual capability.

General Information

• Status: Replaced
• Publication Date: 03-Nov-2013
• ICS: 29.240.01 - Power transmission and distribution networks in general
• Technical Committee: TC 115 - High Voltage Direct Current (HVDC) transmission for DC voltages above 100 kV
• Drafting Committee: WG 2 - TC 115/WG 2
• Current Stage: DELPUB - Deleted Publication
• Start Date: 30-Jun-2017
• Completion Date: 26-Sep-2018

Relations

• Replaced By: IEC TR 62672:2018 - Reliability and availability evaluation of HVDC systems
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC/TS 62672-1


®


Edition 1.0 2013-11



TECHNICAL



SPECIFICATION






Reliability and availability evaluation of HVDC systems –
Part 1: HVDC systems with line commutated converters


IEC/TS 62672-1:2013(E)

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IEC/TS 62672-1



®



Edition 1.0 2013-11







TECHNICAL





SPECIFICATION






















Reliability and availability evaluation of HVDC systems –

Part 1: HVDC systems with line commutated converters




























INTERNATIONAL

ELECTROTECHNICAL

COMMISSION

PRICE CODE
X


ICS 29.240.01 ISBN 978-2-8322-1182-3



  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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– 2 – TS 62672-1  IEC:2013(E)


CONTENTS


FOREWORD . 5

1 Scope . 7


2 Normative references . 7

3 Terms, definitions and abbreviations . 8

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 Abbreviations and symbols . 11
4 Classification of HVDC transmission system equipment . 12
4.1 General . 12
4.2 AC and auxiliary equipment (AC-E) . 12
4.2.1 General . 12
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 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) . 13
4.2.7 Other AC switchyard equipment (AC-E.SW) . 13
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
4.4 DC control and protection equipment (C-P) . 14
4.4.1 General . 14
4.4.2 Local control and protection (C-P.L) . 14
4.4.3 Master control and protection (C-P.M) . 14
4.4.4 Telecommunications equipment (C-P.T) . 14
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) . 15
4.5.6 DC earth electrode (DC-E.GE) . 15
4.5.7 DC earth electrode line (DC-E.EL) . 15
4.5.8 Other DC switchyard and valve hall equipment (DC-E.O) . 15
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) . 16
4.8 External (EXT) . 16
5 Classification and severity of fault events and restoration codes . 16

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TS 62672-1  IEC:2013(E) – 3 –


5.1 Classification of fault events . 16

5.2 Severity codes . 17

5.3 Restoration codes . 18

6 Instructions for compilation of report . 18

6.1 General . 18

6.2 General instructions . 18

6.3 Instructions for Table 2 and Table 3 . 19

6.3.1 Section 1 . 19

6.3.2 Section 2 . 19

6.3.3 Sections 3, 4 and 5 . 19
6.3.4 Section 6 . 20
6.3.5 Section 7 . 20
6.4 Instructions for Table 4 and Table 5 . 23
6.4.1 Forced outages – Table 4 . 23
6.4.2 Scheduled outages – Table 5 . 23
6.5 Instructions for Table 6 . 25
6.6 Instructions for Table 7 . 26
6.7 Instructions for Table 8 . 26
6.8 Instructions for Table 9 . 27
7 Interpretation and evaluation of reports . 28
7.1 Calculation of outage duration . 28
7.2 External events . 28
7.3 Protective operation . 28
7.4 Performance of special controls . 28
Annex A (informative) Outage log form and examples . 30
A.1 Example of an outage log . 30
A.2 Examples of application of rule f) of 6.3 scheduled outage during a forced
outage . 32
A.2.1 Case 1: Scheduled outage does not increase ODF or extends
outage duration . 32
A.2.2 Case 2: Scheduled outage increases ODF . 33
A.3 Examples of application of rule g) of 6.3 second outage during an outage . 34
A.3.1 Case 1: Second outage does not increase ODF or extends
outage duration . 34
A.3.2 Case 2: Second outage extends duration . 35

A.3.3 Case 3: Second outage with variable ODF . 36
Annex B (informative) Sample annual report . 37
Bibliography . 43

Figure A.1 – Scheduled outage does not increase ODF or extends outage duration . 32
Figure A.2 – Scheduled outage increases ODF . 33
Figure A.3 – Second outage does not increase ODF or extends outage duration . 34
Figure A.4 – Second outage extends duration . 35
Figure A.5 – Second outage with variable ODF . 36

Table 1 – Classification of fault events . 17
Table 2 – DC system performance for back-to-back systems and for two terminal
systems reporting jointly (corresponding to Table 1 of Cigré TB 346:2008) . 21

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– 4 – TS 62672-1  IEC:2013(E)


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

346:2008) . 22

Table 4 – Forced outages HVDC substation (corresponding to Table 2FS of Cigré TB

346:2008) . 24

Table 5 – Scheduled outages HVDC substation (corresponding to Table 2 SS of Cigré

TB 346:2008) . 24


Table 6 – HVDC overhead line protection operations (corresponding to Table 3 of

Cigré TB 346:2008). 25

Table 7 – AC system faults and commutation failure starts (back-to-back, two terminal

or multi-terminal systems) (corresponding to Table 4 of Cigré TB 346:2008) . 26
Table 8 – Converter unit hours and semiconductor devices failed (corresponding to
Table 5 of Cigré TB 346:2008) . 27
Table 9 – Forced outage summary (corresponding to Table 6 of Cigré TB 346:2008) . 29
Table A.1 – Example of an outage log. 30
Table B.1 – DC system performance for two terminal systems reporting jointly . 37
Table B.2 – Forced outages HVDC substation . 38
Table B.3 – Scheduled outages HVDC substation . 39
Table B.4 – HVDC overhead line protection operations . 40
Table B.5 – AC system faults and commutation failure starts . 40
Table B.6 – Converter unit hours and semiconductor devices failed . 41
Table B.7 – Forced outage summary . 42

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TS 62672-1  IEC:2013(E) – 5 –


INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________



RELIABILITY AND AVAILABILITY EVALUATION OF HVDC SYSTEMS –



Part 1: HVDC systems with line commutated converters



FOREWORD

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The main task of IEC technical committees is to prepare International Standards. In
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• the required support cannot be obtained for the publication of an International Standard,
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• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC/TS 62672-1, which is a technical specification, has been prepared by IEC technical
committee 115: High voltage direct current (HVDC) transmission for DC voltages above
100 kV.

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– 6 – TS 62672-1  IEC:2013(E)


The text of this technical specification is based on the following documents:


Enquiry draft Report on voting

115/68/DTS 115/75/RVC



Full information on the voting for the approval of this technical specification can be found in

the report on voting indicated in the above table.


This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

Annexes A and B are for information only.
A list of all parts in the IEC 62672 series, published under the general title Reliability and
availability evaluation of HVDC systems, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

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TS 62672-1  IEC:2013(E) – 7 –


RELIABILITY AND AVAILABILITY EVALUATION OF HVDC SYSTEMS –



Part 1: HVDC systems with line commutated converters







1 Scope


This part of IEC 62672 applies to all line-commutated high-voltage direct current (HVDC)

transmission systems used for power exchange in utility systems. HVDC stations with voltage
sourced converters (VSC) are not covered.
In order to assess the operational performance of HVDC transmission systems, reliability and
availability need to be evaluated. For this purpose the HVDC users/owners are encouraged to
compile reports on an annual basis based on the recommendations given in this Technical
Specification. The purpose of this part of IEC 62672 is to define a standardized reporting
protocol so that data collected from different HVDC transmission systems can be compared
on an equitable basis. It is recommended that such reports are sent to Cigré SC B4, “HVDC
and Power Electronics” (http://b4.cigre.org) who collects such data and publishes a survey of
HVDC systems throughout the world on a bi-annual basis.
This part of IEC 62672 covers point-to-point transmission systems, back-to-back
interconnections and multi-terminal transmission systems. For point-to-point systems and
back-to-back interconnections, i.e. two-terminal systems, statistics are to be reported based
on the total transmission capability from the sending end to the receiving end measured at a
given point. If, however, the two terminals are operated by different users/owners, or are
composed of equipment of different vintage or of equipment from different suppliers, statistics
can be reported on an individual station basis if so desired by those responsible for reporting.
In such a case, the outage should only be reported under the originating converter station
taking care not to report the same event twice. For distributed multi-terminal systems, i.e.
systems with more than two terminals, statistics are to be reported separately for each
converter station based on its own individual capability.
Multi-terminal systems, incorporating parallel converters but having only two converter
stations on the d.c. line, can be considered as either point-to-point systems or as multi-
terminal systems for purpose of reporting. Therefore, statistics for this special type of multi-
terminal system can be reported based on either total transmission capability or on individual
station capability. If the converters at one station use different technology, converter station
statistics can be reported separately for each different type of capacity if desired. Multiple
bipoles are also to be reported individually. Special mention should be given in the text and in
the tabulations to any common events resulting in bipolar outages.

NOTE Usually the agreement between the purchaser and the turnkey suppliers of the HVDC converter station
includes specific requirements regarding contractual evaluation. Such specific requirements will govern over this
Technical Specification.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60633:1998, Terminology for high-voltage direct current (HVDC) transmission
Amendment 1:2009

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– 8 – TS 62672-1  IEC:2013(E)


3 Terms, definitions and abbreviations


For the purpose of this document, the following terms and definitions apply.


3.1 Outage terms


3.1.1

outage

state in which the HVDC system is unavailable for operation at its rated continuous capacity

due to an event directly related to the converter station equipment or d.c. transmission line


Note 1 to entry: Failure of equipment not needed for power transmission shall not be considered as an outage for
purposes of this evaluation. AC system related outages will be recorded but not included in HVDC system reliability
calculations.
Note 2 to entry: For purposes of this evaluation, outages taken for major reconfiguration or upgrading, such as
addition of converters, shall not be reported.
3.1.2
scheduled outage
outage, which is either planned or which can be deferred until a suitable time
Note 1 to entry: Scheduled outages can be planned well in advance, primarily for preventive maintenance
purposes such as annual maintenance program. During such planned maintenance outage, it is usual to work on
several different equipment or systems concurrently. It is not necessary to allocate such outage time to individual
equipment categories. Only the elapsed time should be reported in Table 5 as “PM”.
Note 2 to entry: Classified under the scheduled outage category are also outages for work which could be
postponed until a suitable time (usually night or weekend) but cannot be postponed until the next planned outage.
Equipment category code in Table 5 should be used to identify the affected equipment. This includes discretionary
outages based on operating policies, user/owner’s preference and maintenance of redundant equipment.
Note 3 to entry: If the scheduled outage is extended due to additional work which would otherwise have
necessitated a forced outage, the excess period is to be counted as a forced outage.
3.1.3
forced outage
state in which equipment is unavailable for normal operation but is not in the scheduled
outage state
3.1.3.1
trips
sudden interruption in transmission by automatic protective action or manual emergency
shutdown
3.1.3.2
other forced outages
other unexpected HVDC equipment problems that force immediate reduction in capacity of
HVDC converter stations or system but do not cause or require a trip
Note 1 to entry: Also in this category are outages caused by start-up or de-block delays caused by HVDC
equipment.
Note 2 to entry: In some cases the opportunity exists during forced outages to perform some of the repairs or
maintenance that would otherwise be performed during the next scheduled outage. See 6.3, rule (f).
3.2 Capacity terms
3.2.1
rated capacity
P
m
maximum capacity (MW), excluding the added capacity available through means of redundant
equipment, for which continuous operation under designed conditions is possible

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TS 62672-1  IEC:2013(E) – 9 –


Note 1 to entry: For two-terminal systems reporting jointly, the rated capacity is referred to a particular point in

the system, usually at one or the other converter station. For multi-terminal systems or two-terminal systems
reporting separately, the rated capacity refers to the rating of the individual converter station.


Note 2 to entry: When the maximum continuous capacity varies according to seasonal conditions, the highest

value can be used as the capacity for the purpose of reports prepared according to this Specification for reason of
simplicity. However this excludes over-load capability such as available during low – ambient temperature.


3.2.2

outage capacity

P
o

capacity reduction (MW) which the outage would have caused if the system were operating at

its rated capacity (P ) at the time of the outage
m

Note 1 to entry: The outage capacity is referred to the same point in the system used for defining P .
m
3.2.3
outage derating factor
ODF
ratio of outage capacity to rated capacity
ODF = P / P
o m
3.3 Outage duration terms
3.3.1
actual outage duration
AOD
time elapsed in decimal hours between the start and the end of an outage
Note 1 to entry: The start of an outage is typically the first switching action related to the outage. The end of an
outage is typically the last switching action related to return of the equipment to operational readiness.
Note 2 to entry: In some contractual evaluations between Purchaser and Supplier, AOD can be subjected to
correction to adjust for long waiting times, administrative delays, non-availability of tools and tackles, non-
availability of spare parts or other needed resources including trained man power, delay in permits etc.
3.3.2
equivalent outage duration
EOD
actual outage duration (AOD) in decimal hours, multiplied by the outage derating factor
(ODF), so as to take account of partial loss of capacity
EOD = AOD × ODF
Note 1 to entry: Each equivalent outage duration (EOD) may be classified according to the type of outa
...