SIST EN IEC 60633:2020

SLOVENSKI STANDARD
SIST EN IEC 60633:2020
01-januar-2020
Nadomešča:
SIST EN 60633:2001
SIST EN 60633:2001/A1:2010
SIST EN 60633:2001/A2:2015
Visokonapetostni enosmerni prenos (HVDC) - Slovar (IEC 60633:2019)
High-voltage direct current (HVDC) transmission - Vocabulary (IEC 60633:2019)
High-voltage direct current (HVDC) transmission - Vocabulary (IEC 60633:2019)
Transport d'énergie en courant continu à haute tension (CCHT) - Vocabulaire (IEC
60633:2019)
Ta slovenski standard je istoveten z: EN IEC 60633:2019
ICS:
01.040.29 Elektrotehnika (Slovarji) Electrical engineering
(Vocabularies)
29.200 Usmerniki. Pretvorniki. Rectifiers. Convertors.
Stabilizirano električno Stabilized power supply
napajanje
SIST EN IEC 60633:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60633:2020

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SIST EN IEC 60633:2020


EUROPEAN STANDARD EN IEC 60633

NORME EUROPÉENNE

EUROPÄISCHE NORM
July 2019
ICS 29.200 Supersedes EN 60633:1999
English Version
High-voltage direct current (HVDC) transmission - Vocabulary
(IEC 60633:2019)
Transport d'énergie en courant continu à haute tension Hochspannungsgleichstrom-Übertragung (HGÜ) - Begriffe
(CCHT) - Vocabulaire (IEC 60633:2019)
(IEC 60633:2019)
This European Standard was approved by CENELEC on 2019-05-30. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 60633:2019 E

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SIST EN IEC 60633:2020
EN IEC 60633:2019 (E)
European foreword
The text of document 22F/480/CDV, future edition 3 of IEC 60633, prepared by SC 22F "Power
electronics for electrical transmission and distribution systems" of IEC/TC 22 "Power electronic
systems and equipment" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60633:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-02-28
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-05-30
document have to be withdrawn

This document supersedes EN 60633:1999.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 60633:2019 was approved by CENELEC as a European
Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60027 (series) NOTE Harmonized as EN 60027 (series)
IEC 60076 (series) NOTE Harmonized as EN 60076 (series)
IEC 60099 (series) NOTE Harmonized as EN 60099 (series)
IEC 60146-1-1 NOTE Harmonized as EN 60146-1-1
IEC 60146-1-3:1991 NOTE Harmonized as EN 60146-1-3:1993 (not modified)
IEC 60700-2 NOTE Harmonized as EN 60700-2
IEC/TR 60919-2:2008 NOTE Harmonized as CLC/TR 60919-2:2010 (not modified)

2

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SIST EN IEC 60633:2020



IEC 60633

®


Edition 3.0 2019-04




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











High-voltage direct current (HVDC) transmission – Vocabulary



Transport d'énergie en courant continu à haute tension (CCHT) – Vocabulaire



















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.200 ISBN 978-2-8322-6812-4




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

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Symbols and abbreviated terms . 5
3.1 Letter symbols . 5
3.2 Subscripts . 6
3.3 Abbreviated terms . 6
4 Graphical symbols . 6
5 General terms related to converter circuits . 6
6 Converter units and valves . 9
7 Converter operating conditions . 12
8 HVDC systems and substations . 15
9 HVDC substation equipment . 19
10 Modes of control . 23
11 Control systems . 23
12 Control functions . 26
Bibliography . 37

Figure 1 – Graphical symbols . 27
Figure 2 – Bridge converter connection . 27
Figure 3 – Example of a converter unit . 28
Figure 4 – Commutation process at rectifier and inverter modes of operation . 29
Figure 5 – Illustrations of commutation in inverter operation . 30
Figure 6 – Typical valve voltage waveforms . 31
Figure 7 – Example of an HVDC substation . 32
Figure 8 – Example of bipolar two-terminal HVDC transmission system . 33
Figure 9 – Example of a multiterminal bipolar HVDC transmission system with parallel
connected HVDC substations . 33
Figure 10 – Example of a multiterminal HVDC transmission system with series
connected HVDC substations . 34
Figure 11 – Simplified steady-state voltage-current characteristic of a two-terminal
HVDC system . 34
Figure 12 – Hierarchical structure of an HVDC control system . 35
Figure 13 – Capacitor commutated converter configurations . 36

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

HIGH-VOLTAGE DIRECT CURRENT
(HVDC) TRANSMISSION – VOCABULARY

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC
Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60633 has been prepared by subcommittee 22F: Power electronics
for electrical transmission and distribution systems, of IEC technical committee 22: Power
electronic systems and equipment.
This third edition cancels and replaces the second edition published in 1998,
Amendment 1:2009 and Amendment 2:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) 40 terms and definitions have been amended and 31 new terms and definitions have been
added mainly on converter units and valves, converter operating conditions, HVDC
systems and substations and HVDC substation equipment;
b) a new Figure 13 on capacitor commutated converter configurations has been added.

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The text of this International Standard is based on the following documents:
CDV Report on voting
22F/480/CDV 22F/491A/RVC

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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HIGH-VOLTAGE DIRECT CURRENT
(HVDC) TRANSMISSION – VOCABULARY



1 Scope
This document defines terms for high-voltage direct current (HVDC) power transmission
systems and for HVDC substations using electronic power converters for the conversion from
AC to DC or vice versa.
This document is applicable to HVDC substations with line commutated converters, most
commonly based on three-phase bridge (double way) connections (see Figure 2) in which
unidirectional electronic valves, for example semiconductor valves, are used. For the thyristor
valves, only the most important definitions are included in this document. A more
comprehensive list of HVDC valve terminology is given in IEC 60700-2.
2 Normative references
There are no normative references in this document.
3 Symbols and abbreviated terms
The list covers only the most frequently used symbols. For a more complete list of the
symbols which have been adopted for static converters, see IEC 60027 (all parts) and other
standards listed in the Bibliography.
3.1 Letter symbols
U direct voltage (any defined value)
d
U nominal no-load direct voltage
d0
U
ideal no-load direct voltage
di0
U rated direct voltage
dN
U phase-to-phase voltage on line side of converter transformer, RMS value including
L
harmonics
U U
rated value of
LN L
U RMS value
no-load phase-to-phase voltage on the valve side of transformer,
ν0
excluding harmonics
I
direct current (any defined value)
d
I rated direct current
dN
I
current on line side of converter transformer, RMS value including harmonics
L
I rated value of I
LN L
I
current on valve side of transformer, RMS value including harmonics
ν
α (trigger) delay angle
β (trigger) advance angle
γ extinction angle
µ overlap angle
p pulse number
q commutation number

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3.2 Subscripts
0 (zero) at no load
N rated value or at rated load
d direct current or voltage
i ideal
L line side of converter transformer
v valve side of converter transformer
max maximum
min minimum
n pertaining to harmonic component of order n
3.3 Abbreviated terms
The following abbreviated terms are always in capital letters and without dots.
HVDC high-voltage direct current
MVU multiple valve (unit) (see 6.3.2)
SCR short-circuit ratio (see 7.32)
ESCR effective short-circuit ratio (see 7.33)
MTDC multiterminal HVDC transmission system (see 8.2.2)
MRTB metallic return transfer breaker (see 9.22)
ERTB earth return transfer breaker (see 9.23)
VDCOL voltage dependent current order limit (see 12.9)
SSTI sub-synchronous torsional interaction (see 10.10)
4 Graphical symbols
Figure 1 shows the specific graphical symbols which are defined only for the purposes of this
document. For a more complete list of the graphical symbols which have been adopted for
static converters, see IEC 60617.
5 General terms related to converter circuits
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE For a more complete list of the terms which have been adopted for static converters, see IEC 60050-551
and IEC 60146-1-1.
5.1
conversion
transfer of energy from AC to DC or vice versa, or a combination of these operations
5.2
converter connection
electrical arrangement of arms and other components necessary for the functioning of the
main power circuit of a converter

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5.3
bridge converter connection
double-way connection comprising six converter arms such that the centre terminals are the
phase terminals of the AC circuit, and that the outer terminals of like polarity are connected
together and are the DC terminals
Note 1 to entry: The double-way connection is illustrated in Figure 2.
5.3.1
uniform bridge
bridge where all converter arms are either controllable or non-controllable
5.3.2
non-uniform bridge
bridge with both controllable and non-controllable converter arms
5.4
converter arm
part of a bridge connecting two points of different potentials within a bridge, for example,
between an AC terminal and a DC terminal
5.4.1
controllable converter arm
converter arm in which the start of forward conduction may be determined by an externally
applied signal
5.4.2
non-controllable converter arm
converter arm in which the start of forward conduction is determined solely by the voltage
applied to its terminals
5.5
by-pass path
low resistance path between the DC terminals of one or several bridges excluding the AC
circuit
Note 1 to entry: The by-pass path may either constitute a unidirectional path, e.g. a by-pass arm (see 5.5.1), or a
by-pass pair (see 5.5.2), or it may constitute a bidirectional path, e.g. a by-pass switch (see 9.30).
5.5.1
by-pass arm
unidirectionally conducting by-pass path connected only between DC terminals, commonly
used with mercury arc valve technology
Note 1 to entry: By-pass arm is not shown in Figure 2.
5.5.2
by-pass pair
two converter arms of a bridge connected to a common AC terminal and forming a by-pass
path
SEE: Figure 2.
5.6
commutation
transfer of current between any two paths with both paths carrying current simultaneously
during this process
Note 1 to entry: Commutation may occur between any two converter arms, including the connected AC phases,
between a converter arm and a by-pass arm, or between any two paths in the circuit.

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5.6.1
line commutation
method of commutation whereby the commutating voltage is supplied by the AC system
5.7
commutating group
group of converter arms which commutate cyclically and independently from other converter
arms and where the commutations are normally not simultaneous
Note 1 to entry: In the case of a bridge, a commutating group is composed of the converter arms connected to a
common DC terminal. In certain cases, e.g. when large currents and/or large commutation inductances are
involved, the commutation in the two commutating groups belonging to the same bridge need not be independent.
SEE: Figure 2.
5.8
commutation inductance
total inductance included in the commutation circuit, in series with the commutating voltage
5.9
pulse number
p
characteristic of a converter connection expressed as the number of non-simultaneous
symmetrical commutations occurring during one cycle of the AC line voltage
Note 1 to entry: The pulse number of a bridge converter connection defined in 5.3 is always p = 6.
5.10
commutation number
q
number of commutations during one cycle of the AC line voltage occurring in each
commutating group
Note 1 to entry: In a bridge converter connection, each commutating group has a commutation number q = 3.
5.11
capacitor commutated converter
converter in which series capacitors are included between the converter transformer and the
valves
SEE: Figure 13 a).
5.12
controlled series capacitor converter
converter in which series capacitors are inserted between the AC filter bus and the AC
network
SEE: Figure 13 b).
5.13
commutating voltage
voltage which causes the current to commutate
[SOURCE: IEC 60050-551:1998, 551-16-02]
5.14
controlled capacitor commutated converter
converter in which controlled series capacitors are included between the converter
transformer and the valves

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5.15
series capacitor converter
converter in which fixed series capacitors are inserted between the AC filter bus and the AC
network
6 Converter units and valves
6.1
converter unit
indivisible operative unit comprising all equipment between the point of common coupling on
the AC side (see 8.24) and the point of common coupling-DC side (see 8.25), essentially one
or more converter bridges, together with one or more converter transformers, converter unit
control equipment, essential protective and switching devices and auxiliaries, if any, used for
conversion
SEE: Figure 3.
6.2
converter bridge
equipment used to implement the bridge converter connection and the by-pass arm, if used
Note 1 to entry: The term "bridge" may be used to describe either the circuit connection or the equipment
implementing that circuit (see 5.3).
6.2.1
anode/cathode valve commutating group
equipment used to implement the converter arms of one commutating group of a bridge with
interconnected anode/cathode terminals
6.3
valve
complete operative controllable or non-controllable valve device assembly, normally
conducting in only one direction (the forward direction), which can function as a converter arm
in a converter bridge
6.3.1
single valve unit
single structure comprising only one valve
6.3.2
multiple valve unit
MVU
single structure comprising more than one valve
Note 1 to entry: Examples of multiple valve units are double valves, quadrivalves and octovalves with two, four
and eight series-connected valves respectively.
Note 2 to entry: This note applies to the French language only.
6.4
main valve
valve in a converter arm
6.5
by-pass valve
valve in a by-pass arm

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6.6
thyristor module
part of a valve comprising a mechanical assembly of thyristors with their immediate auxiliaries
but without valve reactors
Note 1 to entry: Thyristor modules may be elements in the construction of a valve, and/or be interchangeable for
maintenance purposes.
6.7
reactor module
part of a valve, being a mechanical assembly of one or more reactors, used in some valve
designs
Note 1 to entry: Reactor modules may be elements in the construction of a valve.
6.8
valve section
electrical assembly, comprising a number of thyristors and other components, which exhibits
prorated electrical properties of a complete valve
Note 1 to entry: This term is mainly used to define a test object for valve testing purposes.
6.9
valve thyristor level
part of a valve comprising a thyristor, or thyristors connected in parallel, together with their
immediate auxiliaries, and reactor, if any
6.10
valve support
part of the valve which mechanically supports and electrically insulates the active part of the
valve from earth
Note 1 to entry: A part of a valve which is clearly identifiable in a discrete form to be a valve support may not
exist in all designs of valves.
6.11
valve structure
structural components of a valve, required in order to physically support the valve modules
6.12
valve base electronics
VBE
electronic unit, at earth potential, providing the electrical to optical conversion between the
converter control system and the valves
Note 1 to entry: This note applies to the French language only.
6.13
valve electronics
electronic circuits at valve potential(s) which perform control and protection functions for one
or more thyristor levels
6.14
valve arrester
arrester connected across a valve
SEE: Figure 3.
6.15
converter unit arrester
arrester connected across the DC terminals of a converter unit

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SEE: Figure 3.
6.16
converter unit DC bus arrester
arrester connected from the high-voltage DC bus of the converter unit to substation earth
SEE: Figure 3 and Figure 7.
6.17
midpoint DC bus arrester
arrester connected between the midpoint of the two 6-pulse bridges of a 12-pulse converter
unit and substation earth
Note 1 to entry: In some HVDC substation designs, two twelve-pulse converter units are connected in series. In
this case, the midpoint DC bus arrester at the upper twelve-pulse converter unit is not connected to the substation
earth but to the high-voltage DC bus of the lower twelve-pulse converter unit.
SEE: Figure 7.
6.18
valve reactor
reactor(s) connected in series with the thyristors in a valve, for the purpose of limiting the rate
of rise of current at turn-on and voltage during the off-state
Note 1 to entry: Valve reactors may be external to the entire valve or distributed within the valve.
6.19
converter transformer
transformer through which energy is transmitted from an AC system to one or more converter
bridges or vice versa
SEE: Figure 3.
6.19.1
line side windings
converter transformer windings which are connected to the AC system
6.19.2
valve side windings
converter transformer windings which are connected to the AC terminals of one or more
converter bridges
6.20
valve module
part of a valve comprising a mechanical assembly of thyristors with their immediate auxiliaries
and valve reactor(s)
6.21
redundant levels
maximum number of series connected thyristor levels in a valve that may be short-circuited
externally or internally during service without affecting the safe operation of the valve as
demonstrated by type tests, and which if and when exceeded, would require shutdown of the
valve to replace the failed levels or acceptance of increased risk of failures
6.22
valve anode terminal
valve terminal at which the forward current flows into the valve
6.23
valve cathode terminal
valve terminal at which the forward current flows out of the valve

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7 Converter operating conditions
7.1
rectifier operation
rectification
mode of operation of a converter or an HVDC substation when energy is transferred from the
AC side to the DC side
7.2
inverter operation
inversion
mode of operation of a converter or an HVDC substation when energy is transferred from the
DC side to the AC side
7.3
forward direction
conducting direction
direction in which a valve is capable of conducting load current
7.4
reverse direction
non-conducting direction
reverse of the conducting direction
7.5
forward current
current which flows through a valve in the forward direction
7.6
reverse current
current which flows through a valve in the reverse direction
7.7
forward voltage
voltage applied between the anode and cathode terminals of a valve or an arm when the
anode is positive with respect to the cathode
7.8
reverse voltage
voltage applied between the anode and cathode terminals of a valve or an arm when the
anode is negative with respect to the cathode
7.9
conducting state
on-state
condition of a valve when the valve exhibits a low resistance
Note 1 to entry: The valve voltage for this condition is shown in Figure 6.
7.10
valve voltage drop
...