IEC 61148:2011

Terminal markings for valve device stacks and assemblies and for power conversion equipment

IEC 61148:2011 is applicable to the terminal markings for the main circuits of valve device stacks and assemblies, and of integrated conversion equipment. The terminal markings refer to stacks, assemblies and equipment comprising semiconductor valve devices. The object of this standard is to specify a logical alphanumeric marking system for the identification of the external main terminals of the main power circuits in a stack, valve device assembly or integrated conversion equipment, which is applicable for the purpose of reference in circuit diagrams, catalogues, descriptions, and information exchange and storage. In the case of stacks and assemblies, alphanumeric terminal marking systems are indicated for those converter connections which are the most important and most commonly used ones. Terminal marking systems making use of graphic symbols or identifying colours are not considered in this standard. This second edition includes the following significant technical changes with respect to the previous edition:
- the whole document has been rewritten according to the current Directives;
- the identification codes were deleted according to the withdrawal of IEC 60971;
- examples of terminal marking were added, especially for self-commutated converters.

Marquage des bornes de blocs et d'ensembles d'éléments de valve et d'équipement de conversion de puissance

La CEI 61148:2011 s'applique aux marquages des bornes des circuits principaux des blocs et des ensembles d'éléments de valve, ainsi qu'aux équipements intégrés de conversion. Le marquage des bornes se rapporte aux blocs, aux ensembles et aux équipements comprenant des éléments de valve à semiconducteurs. En ce qui concerne les blocs et les ensembles, les systèmes de marquage alphanumériques des bornes sont indiqués pour les montages de convertisseurs les plus importantes et les plus usuelles. Les systèmes de marquage de bornes qui se servent de symboles graphiques ou de couleurs ne sont pas pris en considération dans la présente norme. Cette deuxième édition présente les modifications techniques majeures suivantes par rapport à l'édition antérieure:
- l'ensemble du document a été reformulé conformément aux Directives actuelles;
- les codes d'identification ont été éliminés consécutivement à la suppression de la CEI 60971;
- des exemples de marquages de bornes ont été ajoutés, en particulier pour les convertisseurs auto-commutés.

General Information

• Status: Published
• Publication Date: 19-Oct-2011
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.200 - Rectifiers. Convertors. Stabilized power supply
• Technical Committee: TC 22 - Power electronic systems and equipment
• Drafting Committee: MT 3 - TC 22/MT 3
• Current Stage: PPUB - Publication issued
• Start Date: 31-Oct-2011
• Completion Date: 20-Oct-2011

Standards Content (Sample)

IEC 61148
®

Edition 2.0 2011-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Terminal markings for valve device stacks and assemblies and for power
conversion equipment

Marquage des bornes de blocs et d'ensembles d'éléments de valve et
d'équipement de conversion de puissance
IEC 61148:2011

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THIS PUBLICATION IS COPYRIGHT PROTECTED
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IEC 61148
®

Edition 2.0 2011-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Terminal markings for valve device stacks and assemblies and for power
conversion equipment

Marquage des bornes de blocs et d'ensembles d'éléments de valve et
d'équipement de conversion de puissance

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX T
ICS 29.200 ISBN 978-2-88912-705-4

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

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– 2 – 61148 © IEC:2011
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Method of identifying terminals . 7
5 Terminal marking for valve device stacks and assemblies . 8
5.1 Single and double way connections . 8
5.1.1 General . 8
5.1.2 Single way connections . 9
5.1.3 Double way connections . 11
5.1.4 Combination of connections . 13
5.2 Bi-directional connections . 14
5.2.1 Inseparable connections of pair of anti-parallel arms . 14
5.2.2 Combinations of pairs of anti-parallel arms . 15
6 Marking of external main terminals of integrated conversion equipment . 18
6.1 A.C. terminals . 18
6.1.1 Single-phase a.c. system . 18
6.1.2 Three-phase a.c. system . 18
6.1.3 A.C. conversion equipment with a.c. terminals on supply and load
side, for three-phase systems . 18
6.2 D.C. terminals . 19
6.2.1 General . 19
6.2.2 A.C./D.C. conversion equipment . 19
6.2.3 Double conversion equipment with reversible polarity of d.c.
terminals . 19
6.2.4 D.C. conversion equipment with d.c. terminals on the supply and load
sides . 19
6.2.5 Terminal for connection to mid-wire conductor . 20
6.2.6 Conversion equipment with more than one converter section with
separate terminal sets on supply and load side. 20
6.2.7 Conversion equipment in which the external main terminals are
formed by the main terminals of the assembly(ies) incorporated in the
equipment . 20
6.3 Marking of gate terminals . 22
6.3.1 General . 22
6.3.2 For thyristors . 22
6.3.3 For power transistors . 24

Figure 1 – Typical markings in single arm connections . 9
Figure 2 – Star connection with two arms . 10
Figure 3 – Star connection with three arms . 10
Figure 4 – Three groups with two arms . 11
Figure 5 – Two groups with three arms . 11
Figure 6 – Assembly for d.c. chopper . 11
Figure 7 – Pair of arms . 12
Figure 8 – Bridge connection . 12

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61148 © IEC:2011 – 3 –
Figure 9 – Double bridge connection . 13
Figure 10 – Anti-parallel bridge connection . 13
Figure 11 – Series connection of bridges . 14
Figure 12 – Fully controllable anti-parallel pairs . 14
Figure 13 – Half-controllable anti-parallel pairs . 14
Figure 14 – Example for six-phase supply . 15
Figure 15 – Three-phase star connection . 16
Figure 16 – Three-phase star connection with neutral . 16
Figure 17 – Double two-phase star connection with neutral . 16
Figure 18 – Polygon connection . 16
Figure 19 – Legs for voltage stiff converters . 17
Figure 20 – Bridge connection for voltage stiff converter (two-level) . 17
Figure 21 – Three-level connection for inverter . 18
Figure 22 – Single-phase a.c./d.c. converter . 20
Figure 23 – Double converter . 21
Figure 24 – Three-phase rectifier with two sections and d.c. side centre tap for
connection to a mid-wire conductor . 21
Figure 25 – Direct (or indirect) d.c. converter with two independent sections . 21
Figure 26 – Indirect (or direct) a.c. converter . 22
Figure 27 – Three-phase star connection with neutral . 23
Figure 28 – Bridge connection . 23
Figure 29 – Thyristor with gate unit . 23
Figure 30 – Three-phase star connection with power transistors . 24
Figure 31 – Pair of power transistors with anti-parallel diodes . 24
Figure 32 – Power transistor with gate driver . 24

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

TERMINAL MARKINGS FOR VALVE DEVICE
STACKS AND ASSEMBLIES AND FOR
POWER CONVERSION EQUIPMENT


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
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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 61148 has been prepared by IEC technical committee 22: Power
electronic systems and equipment.
This second edition cancels and replaces the first edition published in 1992. This second
edition constitutes a technical revision.
This second edition includes the following significant technical changes with respect to the
previous edition:
– the whole document has been rewritten according to the current Directives;
– the identification codes were deleted according to the withdrawal of IEC 60971;
– examples of terminal marking were added, especially for self-commutated converters.

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61148 © IEC:2011 – 5 –
The text of this international standard is based on the following documents:
FDIS Report on voting
22/185/FDIS 22/188/RVD

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 publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
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
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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TERMINAL MARKINGS FOR VALVE DEVICE
STACKS AND ASSEMBLIES AND FOR
POWER CONVERSION EQUIPMENT



1 Scope
This International Standard is applicable to the terminal markings for the main circuits of valve
device stacks and assemblies, and of integrated conversion equipment. The terminal
markings refer to stacks, assemblies and equipment comprising semiconductor valve devices.
NOTE 1 Terminal markings for auxiliary circuits, including gate terminals and non-integrated conversion
equipment with separate manufacturing of its components and their interconnection only after installation on site,
are not considered in this standard.
For such equipment the relevant standards, if any, for the individual components apply.
Gate terminal markings are given in 6.3.
Terminal markings for other circuits such as protective conductor are not considered in this standard.
The object of this standard is to specify a logical alphanumeric marking system for the
identification of the external main terminals of the main power circuits in a stack, valve device
assembly or integrated conversion equipment, which is applicable for the purpose of
reference in circuit diagrams, catalogues, descriptions, and information exchange and storage.
In the case of stacks and assemblies, alphanumeric terminal marking systems are indicated
for those converter connections which are the most important and most commonly used ones.
Terminal marking systems making use of graphic symbols or identifying colours are not
considered in this standard.
NOTE 2 The terminals of auxiliary circuits should be marked such that they may be clearly identified.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-551, International Electrotechnical Vocabulary – Part 551: Power electronics
IEC 60146-1-1, Semiconductor converters – General requirements and line commutated
converters – Part 1-1: Specification of basic requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-551,
IEC 60146-1-1 and the following apply.
3.1
external main terminals
terminals of the main power circuit of the stack, assembly or equipment to which the external
power supply or the load are connected
NOTE 1 In the following clauses this term is abbreviated to "terminals”.

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61148 © IEC:2011 – 7 –
NOTE 2 For stacks and assemblies the main power circuit is formed by the principal valve arms.
3.2
integrated conversion equipment
factory-built conversion equipment the components of which are assembled, interconnected
and tested in the factory thus forming a complete equipment
NOTE 1 Equipment composing one or more semiconductor switches is considered to be conversion equipment.
NOTE 2 For transport purpose, the equipment can be divided in several cubicles that will have to be reassembled
at the site.
3.3
anode
electrode capable of emitting positive charge carriers to and/or receiving negative charge
carriers from the medium of lower conductivity
[IEC 60050-151: 2001, 151-13-02]
NOTE 1 The direction of electric current is from the external circuit, through the anode, to the medium of lower
conductivity.
NOTE 2 In some cases (e.g. electrochemical cells), the term "anode" is applied to one or another electrode,
depending on the electric operating condition of the device. In other cases (e.g. electronic tubes and
semiconductor devices), the term "anode" is assigned to a specific electrode.
3.4
cathode
electrode capable of emitting negative charge carriers to and/or receiving positive charge
carriers from the medium of lower conductivity
[IEC 60050-151:2001, 151-13-03]
NOTE 1 The direction of electric current is from the medium of lower conductivity, through the cathode, to the
external circuit.
NOTE 2 In some cases (e.g. electrochemical cells), the term "cathode" is applied to one or another electrode,
depending on the electric operating condition of the device. In other cases (e.g. electronic tubes and
semiconductor devices), the term "cathode" is assigned to a specific electrode.
4 Method of identifying terminals
The use of alphanumeric notation should be preferred to any alternative marking, as in j).
a) The marking of the terminals should be based on alphanumeric notation employing capital
(upper case) roman characters and Arabic numerals.
NOTE 1 It is recommended that the reference letters for d.c. terminals are chosen from the first part and
reference letters for a.c. terminals from the second part of the alphabet.
NOTE 2 In those cases where difficulties could otherwise arise in correspondence, documents, etc., the use of
small (lower case) letters, which have the same significance, is permitted.
b) Letters “I” and “O” shall not be used to prevent confusion with the numerals “1” and “0”.
c) For converter connections with unchangeable polarity, “+” or “pos” may be used to the
positive terminal and “−” or “neg” may be used to the negative terminal.
NOTE 3 In this standard, if not otherwise stated, the term “polarity” is used with respect to the direction of current
flow.
d) The complete notation is based on the use of combinations of alternate alphabetical and
numerical character groups, each containing one or more letters and/or digits.
e) Terminals with identical basic markings according to Clause 5 and Clause 6 should be
distinguished by a reference number in a naturally ascending sequence according to the
sequence of operation or the direction of current flow starting with 1 and following the
basic terminal markings, for example X1 – X2 – X3, Y1 – Y2 – Y3.

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– 8 – 61148 © IEC:2011
f) Terminals with identical basic markings according to Clause 5 and Clause 6 in two or more
similar terminal groups should be distinguished by a reference number in a naturally
ascending sequence starting with 1 and preceding the basic terminal markings, for
example 1X – 1Y – 1Z, 2X –2Y – 2Z, etc.
g) If, for further differentiation of terminal groups, further letters or numbers are required in
addition to the terminal marking in Clause 5 and Clause 6 and in f), such additional
marking should be placed before this marking, separated from it by a full stop.
h) The marking shall be clearly legible and durable.
i) The marking of the main terminals according to Clause 5 to Clause 6 shall be shown
clearly on the corresponding circuit diagram. This shall also be observed for main and
auxiliary terminals not considered in this standard.
j) In cases where the construction mode or size of a stack or assembly prevents the
application of the alphanumeric notation for terminal marking, the terminals shall be
clearly identified by another applicable method, for example by identifying colours or
graphic symbols which, however, are not the subject of this standard.
5 Terminal marking for valve device stacks and assemblies
5.1 Single and double way connections
5.1.1 General
The external main terminals of an individual principal arm or of a number of inter-connected
principal arms of the same polarity shall be marked by a capital letter corresponding to the
polarity of the end of the arm(s) connected to the terminal to be identified, also in cases
where the arms comprise, in addition to the valve devices, further components, for example
fuses, reactors, capacitors, etc.
The terminal for a common connection point of arms ending with the same polarity shall be
identified by the capital letter M placed behind the identification letter for its polarity.
– End terminal of a principal arm forming:
• an anode: basic terminal marking A
• a cathode: basic terminal marking K
NOTE Although other markings may be used for valve devices, e.g. C and B or D and S, A and K are used for
arms.
– Terminal for interconnection point of the anode of a principal arm with the cathode of a
second principal arm:
• basic terminal marking AK
– Terminal for the interconnection point of two or more principal arms of the same polarity
forming:
• an anode: basic terminal marking AM
• a cathode: basic terminal marking KM
– Terminal for an interconnection point of the same number of anodes and cathodes of
principal arms:
• basic terminal marking AKM
– If the valve device stack or assembly is used in a specific converter or semiconductor
switch, and its terminals are connected to terminals of the converter or switch, the terminal
marking of which may be used:
• d.c. terminal: alternative terminal marking C, D
• a.c. terminal: alternative terminal marking U, V, W
– For converter connections with unchangeable polarity of the d.c. terminals the following
marking may be used alternatively:

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61148 © IEC:2011 – 9 –
• the sign + for the positive terminal
• the sign − for the negative terminal
If several identical principal arms are combined to a connection in a single stack or assembly,
the end terminals with the same polarity shall be distinguished by natural reference numbers,
for example 1, 2, 3. placed behind the basic terminal markings, i.e. A1 – A2 – A3, K1 – K2 –
K3.
5.1.2 Single way connections
5.1.2.1 Single arm connection
Terminal marking:
– Anode side: A
– Cathode side: K
EXAMPLES: See Figure 1. Examples are shown for rectifier diode, P-gate reverse blocking
triode thyristor, PNP bipolar transistor, NPN bipolar transistor, N-channel IGBT and N-channel
Type C enhancement type MOSFET.
NOTE 1 The terminals of an individual principal arm which is intended to be part of a converter connection
comprising several principal arms may be marked like those of a single arm connection.
NOTE 2 The marking of terminals connected to auxiliary arms only is not considered in this standard.
NOTE 3 The arm which consists of several valve devices connected series and/or parallel is considered to be one
arm. The arm which consists of switched valve device and series diode for reverse blocking is also considered to
be one arm.
NOTE 4 In some kinds of controllable valve devices, rectifier diodes connected anti-parallel may be integrated in
common semiconductor chip or packaged in a common case. If the rectifier diodes are used, these arms are
considered as half-controllable anti-parallel pairs. See 5.2.1.

A K
A K
A K
A K
A K
A K
IEC  208 7/11

Figure 1 – Typical markings in single arm connections

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5.1.2.2 Centre tap and star connection
The m principal arms with one and the same polarity connected to a common point, forming
the d.c. terminal (m being a whole number equal to or greater than 2):
– Cathodes forming the d.c. terminal:
• Marking of individual arm terminals: A1, A2 . Am
• Marking of common d.c. terminal: KM
• For diode rectifiers admissible: +
– Anodes forming the d.c. terminal:
• Marking of individual arm terminals: K1, K2 . Km
• Marking of common d.c. terminal: AM
• For diode rectifiers admissible: −
EXAMPLES: See Figure 2 and Figure
...