IEC 62590:2019

Railway applications - Fixed installations - Electronic power converters for substations

IEC 62590:2019 specifies the requirements for the performance of all fixed installations electronic power converters, using controllable and/or non-controllable electronic valves, intended for traction power supply. The devices can be controlled by means of current, voltage or light. Non-bistable devices are assumed to be operated in the switched mode.
This document applies to fixed installations of the following electric traction systems:
- railways,
- guided mass transport systems such as: tramways, light rail systems, elevated and underground railways, mountain railways, trolleybuses.
This standard is based on EN 50328. This second edition cancels and replaces the first edition published in 2010. This edition includes the following significant technical changes with respect to the previous edition:
a) Incorporation of DC converters.
b) Correction of the clearances and withstand voltages due to erroneous use of PD in former edition.
c) adaption of structure, adaption of vocabulary, removal of unused term and abbreviations.

General Information

• Status: Published
• Publication Date: 22-Aug-2019
• ICS: 45.060.01 - Railway rolling stock in general
• Technical Committee: TC 9 - Electrical equipment and systems for railways
• Drafting Committee: WG 50 - TC 9/WG 50
• Current Stage: PPUB - Publication issued
• Start Date: 23-Aug-2019
• Completion Date: 12-Jul-2019

Relations

• Replaced By: IEC 62590-3-1:2022 - Railway applications - Fixed installations - Electronic power converters - Part 3-1: AC traction applications - Electronic power compensators
• Effective Date: 26-Oct-2025
• Replaced By: IEC 62590-1:2025 - Railway applications - Electronic power converters for fixed installations - Part 1: General requirements
• Effective Date: 26-Oct-2025
• Replaced By: IEC 62590-2-1:2025 - Railway applications - Electronic power converters for fixed installations - Part 2-1: DC traction applications - Uncontrolled rectifiers
• Effective Date: 26-Oct-2025
• Revises: IEC 62590:2010 - Railway applications - Fixed installations - Electronic power converters for substations
• Effective Date: 05-Sep-2023

Overview

IEC 62590:2019 - "Railway applications - Fixed installations - Electronic power converters for substations" - specifies performance, rating and test requirements for fixed-installation electronic power converters used in traction power supply. This international standard covers converters employing controllable and non‑controllable electronic valves (controlled by current, voltage or light) and assumes non‑bistable devices operate in switched mode. It applies to railways and guided mass transit systems (tramways, light rail, elevated/underground railways, mountain railways, trolleybuses). Edition 2.0 (2019) cancels and replaces the 2010 edition and incorporates key updates including the addition of DC converters and corrections to clearance/withstand voltage rules.

Key topics and technical requirements

• Scope and classifications: Types of traction converters, valve device classifications and purposes (rectification, inversion, DC conversion).
• Rated values and load capabilities: Definitions for current, voltage and duty classes; guidance for unsymmetrical loading of parallel converters.
• Service conditions: Environmental and electrical service conditions, cooling codes and standardized duty classes for rating equipment.
• Insulation coordination and clearances: Insulation levels and revised clearance/withstand voltage requirements (correction from prior edition).
• Thermal management: Cooling method codes, temperature-rise testing and calculation of the virtual junction temperature (Annex B) for semiconductor device current capability.
• Electromagnetic compatibility (EMC) and harmonic distortion requirements for traction converters.
• Line‑commutated converter specifics: Connections, calculation factors and direct voltage harmonic content.
• Testing and verification: Test schedule and procedures including insulation tests, light-load and full-load functional tests, power‑loss determination, temperature‑rise, protective device checks, short‑time withstand and EMC tests (see Clause 8 and Table 7).

Practical applications and users

IEC 62590:2019 is essential for:

• Substation equipment manufacturers designing and producing traction converters and DC link systems.
• System integrators and design engineers specifying converter performance, cooling and insulation coordination for fixed installations.
• Procurement teams and asset owners (railway operators, transit authorities) preparing technical specifications and acceptance tests.
• Testing laboratories and certification bodies performing acceptance and type tests per the standard.
• Maintenance and safety engineers assessing failure modes, thermal limits and EMC compliance.

Practical use cases include specifying converter ratings for new substations, validating supplier tenders, verifying insulation and EMC performance, and ensuring thermal margins for semiconductor devices.

Related standards

• Based on EN 50328 (harmonization reference).
• Refer to other IEC documents for complementary topics (insulation, EMC, electrotechnical vocabulary) as indicated in the normative references of IEC 62590.

Keywords: IEC 62590:2019, electronic power converters, railway substations, traction power supply, DC converters, insulation coordination, EMC, virtual junction temperature, converter testing.

Standards Content (Sample)

IEC 62590 ®
Edition 2.0 2019-08
INTERNATIONAL
STANDARD
Railway applications – Fixed installations – Electronic power converters for
substations
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IEC 62590 ®
Edition 2.0 2019-08
INTERNATIONAL
STANDARD
Railway applications – Fixed installations – Electronic power converters for

substations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 45.060.01 ISBN 978-2-8322-7066-0

– 2 – IEC 62590:2019  IEC 2019
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
3.1 Semiconductor devices and combinations . 9
3.2 Arms and connections . 10
3.3 Controllability of converter arms . 11
3.4 Commutation, quenching and commutation circuitry . 11
3.5 Commutation characteristics . 12
3.6 Rated values . 15
3.7 Load capabilities . 16
3.8 Specific voltages, currents and factors . 17
3.9 Definitions related to virtual junction temperature . 18
3.10 Cooling . 18
3.11 Electromagnetic compatibility and harmonic distortion . 19
4 Symbols . 19
5 Operation of semiconductor power equipment and valve devices . 21
5.1 Classification of traction supply power converters and valves . 21
5.1.1 Types of traction supply power converters . 21
5.1.2 Purpose of conversion . 21
5.1.3 Classification of semiconductor valve devices . 21
5.2 Basic calculation factors for line commutated converters . 22
5.2.1 Voltage . 22
5.2.2 Voltage characteristics and transition current . 22
6 Service conditions . 23
6.1 Code of identification of cooling method . 23
6.1.1 Letter symbols to be used . 23
6.1.2 Arrangement of letter symbols . 24
6.2 Environmental conditions . 24
6.2.1 Ambient air circulation . 24
6.2.2 Normal service conditions . 25
6.2.3 Special service conditions . 26
6.3 Electrical service conditions . 26
6.3.1 General . 26
6.3.2 Limiting values as basis of rating . 26
6.3.3 DC traction supply voltage . 28
7 Converter equipment and assemblies . 28
7.1 Losses and efficiency . 28
7.1.1 General . 28
7.1.2 Included losses . 28
7.2 Power factor . 28
7.3 Electromagnetic compatibility (EMC) . 29
7.4 Rated values for converters . 29
7.4.1 General . 29

7.4.2 Current values . 29
7.4.3 Capability for unsymmetrical load of a 12-pulse converter in parallel
connection . 31
7.4.4 Semiconductor device failure conditions . 32
7.5 Mechanical characteristics . 32
7.5.1 General . 32
7.5.2 Earthing . 32
7.5.3 Degree of protection . 33
7.6 Insulation coordination . 33
7.7 Specifics of line commutated rectifiers . 33
7.7.1 Electrical connections . 33
7.7.2 Calculation factors . 35
7.7.3 Direct voltage harmonic content . 35
8 Tests . 35
8.1 General . 35
8.1.1 Overview . 35
8.1.2 Performance of tests . 36
8.1.3 Test schedule . 36
8.2 Test specifications . 36
8.2.1 Insulation tests . 36
8.2.2 Light load functional test . 38
8.2.3 Load test . 38
8.2.4 Power loss determination . 39
8.2.5 Temperature-rise test . 39
8.2.6 Checking of auxiliary devices . 40
8.2.7 Checking of the properties of the control equipment . 40
8.2.8 Checking of the protective devices . 41
8.2.9 Short-time withstand current test . 41
8.2.10 EMC test . 41
8.2.11 Additional tests . 41
9 Marking . 41
9.1 Rating plate . 41
9.2 Main circuit terminals . 42
Annex A (informative) Information required . 43
A.1 General . 43
A.2 Diode rectifiers . 43
A.2.1 Procurement specification . 43
A.2.2 Supplier's tender specification . 44
A.2.3 Information and data to be given by the supplier during the delivery
stage . 44
A.3 Controlled converters and inverters. 45
A.3.1 Procurement specification . 45
A.3.2 Supplier's tender specification . 46
A.4 Frequency converters (direct and DC link converters) . 46
A.4.1 Procurement specification . 46
A.4.2 Supplier's tender specification . 47
A.5 DC converters . 48
A.5.1 Procurement specification . 48
A.5.2 Supplier’s tender specification . 49

– 4 – IEC 62590:2019  IEC 2019
Annex B (informative) Determination of the current capability through calculation of
the virtual junction temperature . 51
B.1 General . 51
B.2 Approximation of the shape of power pulses applied to the semiconductor
device . 51
B.3 Superposition method for the calculation of temperature . 52
B.4 Calculation of virtual junction temperature for continuous load . 53
B.4.1 General . 53
B.4.2 Calculation of mean value of virtual junction temperature . 53
B.4.3 Calculation of maximum instantaneous virtual junction temperature . 53
B.5 Calculation of virtual junction temperature for cyclic loads . 54
B.6 Examples for typical applications . 55
Annex C (informative) Index of definitions . 57
Bibliography . 59

Figure 1 – Illustration of angles . 14
Figure 2 – Voltage regulation . 23
Figure 3 – AC voltage waveform . 27
Figure B.1 – Approximation of the shape of power pulses . 52
Figure B.2 – Calculation of the virtual junction temperature for continuous load . 53
Figure B.3 – Calculation of the virtual junction temperature for cyclic load . 54

Table 1 – Letter symbols for cooling mediums and heat transfer agents . 23
Table 2 – Letter symbols for methods of circulation . 23
Table 3 – Standardized duty classes . 30
Table 4 – Semiconductor device failure conditions . 32
Table 5 – Insulation levels for AC/DC and DC converters . 33
Table 6 – Connections and calculation factors for line commutated converters . 34
Table 7 – Summary of tests . 36
Table 8 – Insulation levels for AC/DC and DC converters . 38
Table B.1 – Examples for typical applications . 55

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RAILWAY APPLICATIONS – FIXED INSTALLATIONS –
ELECTRONIC POWER CONVERTERS FOR SUBSTATIONS

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
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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.
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62590 has been prepared by IEC technical committee 9: Electrical
equipment and systems for railways.
This standard is based on EN 50328.
This second edition cancels and replaces the first edition published in 2010. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Incorporation of DC converters.
b) Correction of the clearances and withstand voltages due to erroneous use of PD in former
edition.
c) Adaption to current ISO/IEC directive part 2, adaption of structure, adaption of vocabulary,
removal of unused term and abbreviations.
The text of this standard is based on the following documents:

– 6 – IEC 62590:2019  IEC 2019
FDIS Report on voting
9/2502/FDIS 9/2516/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 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.
A bilingual version of this publication may be issued at a later date.

INTRODUCTION
Semiconductor converters for traction power supply differ from other converters for industrial
use due to special electrical service conditions and due to the large range of load variation and
the peculiar characteristics of the load.
For these reasons IEC 60146-1-1 does not fully cover the requirements of railway applications
and the decision was taken to have a specific standard for this use.
Converter transformers for fixed installations of railway applications are covered by IEC 62695.
Harmonization of the rated values and tests of the whole converter group are covered by
IEC 62589.
– 8 – IEC 62590:2019  IEC 2019
RAILWAY APPLICATIONS – FIXED INSTALLATIONS –
ELECTRONIC POWER CONVERTERS FOR SUBSTATIONS

1 Scope
This document specifies the requirements for the performance of all fixed installations electronic
power converters, using controllable and/or non-controllable electronic valves, intended for
traction power supply.
The devices can be controlled by means of current, voltage or light. Non-bistable devices are
assumed to be operated in the switched mode.
This document applies to fixed installations of the following electric traction systems:
• railways,
• guided mass transport systems such as: tramways, light rail systems, elevated and
underground railways, mountain railways, trolleybusses.
This document does not apply to:
• cranes, transportable platforms and similar transportation equipment on rails,
• suspended cable cars,
• funicular railways.
This document applies to diode rectifiers, controlled rectifiers, DC converters, inverters and
frequency converters.
The equipment covered in this document is the converter itself.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 60050-811:2017, International electrotechnical vocabulary – Part 811: Electric traction
IEC 60146 (all parts), Semiconductor convertors
IEC TR 60146-1-2:2011, Semiconductor converters – General requirements and line
commutated converters – Part 1-2: Application guide
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60721 (all parts), Classification of environmental conditions
IEC 60721-3-3:1994, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 3: Stationary use at
weatherprotected locations
AMD1:1995
AMD2:1996
IEC 60721-3-4:1995, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 4: Stationary use at non-
weatherprotected locations
AMD1:1996
IEC 60850:2014, Railway applications – Supply voltages of traction systems
IEC 61000-2-4:2002, Electromagnetic compatibility (EMC) – Part 2-4: Environment –
Compatibility levels in industrial plants for low-frequency conducted disturbances
IEC 61000-2-12:2003, Electromagnetic compatibility (EMC) – Part 2-12: Environment –
Compatibility levels for low-frequency conducted disturbances and signalling in public medium-
voltage power supply systems
IEC 61992-7-1:2006, Railway applications – Fixed installations – DC switchgear – Part 7-1:
Measurement, control and protection devices for specific use in DC traction systems –
Application guide
IEC 62236 (all parts), Railway applications – Electromagnetic compatibility
IEC 62236-5:2018, Railway applications – Electromagnetic compatibility – Part 5: Emission and
immunity of fixed power supply installations and apparatus
IEC 62497-1:2010, Railway applications – Insulation coordination – Part 1: Basic requirements
– Clearances and creepage distances for all electrical and electronic equipment
3 Terms and definitions
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 An alphabetical index is given in Annex C.
3.1 Semiconductor devices and combinations
3.1.1
semiconductor device
device whose essential characteristics are due to the flow of charge carriers within a
semiconductor
[SOURCE: IEC 60050-521: 2002, 521-04-01, modified – note omitted]
3.1.2
(valve device) stack
a single structure of one or more electronic valve devices with its (their) associated mounting(s)
and auxiliaries if any
[SOURCE: IEC 60050-551:1998, 551-14-12]

– 10 – IEC 62590:2019  IEC 2019
3.1.3
(valve device) assembly
an electrically and mechanically combined assembly of electronic valve devices or stacks,
complete with all its connections and auxiliaries in its own mechanical structure
[SOURCE: IEC 60050-551:1998, 551-14-13]
3.1.4
electronic power converter
operative unit for power conversion comprising one or more assemblies of semiconductor
devices
Note 1 to entry: The transformers are described in IEC 62695
[SOURCE: IEC 60050-551:1998, 551-12-01, modified – “electronic” has been omitted.
“electronic valve devices, transformers and filters if necessary and auxiliaries if any” has been
replaced with “assemblies of semiconductor devices”. The note 1 to entry has been omitted.]
3.1.5
trigger equipment
equipment which provides suitable trigger pulses from a control signal for controllable valve
devices in a converter or power switch including timing or phase shifting circuits, pulse
generating circuits and usually power supply circuits
3.1.6
system control equipment
equipment associated with a converter equipment or system which performs automatic
adjustment of the output characteristics as a function of a controlled quantity
3.2 Arms and connections
3.2.1
(valve) arm
a part of the circuit of an electronic power converter or switch bounded by any two AC or DC
terminals and including one or more simultaneously conducting electronic valve devices
connected together and other components if any
[SOURCE: IEC 60050-551:1998, 551-15-01]
3.2.2
principal arm
a valve arm involved in the major transfer of power from one side of the converter or electronic
switch to the other
Note 1 to entry: Depending on the mode of operation a principal arm may act as an auxiliary arm or vice versa.
[SOURCE: IEC 60050-551:1998, 551-15-02]
3.2.3
converter connection
the electrical arrangement of valve arms and other components essential for the function of the
main power circuit of a converter
[SOURCE: IEC 60050-551:1998, 551-15-10]
3.2.4
uniform connection
a connection with either all principal arms controllable or all principal arms non-controllable

[SOURCE: IEC 60050-551:1998, 551-15-15]
3.2.5
non-uniform connection
a connection with both controllable and non-controllable principal arms
[SOURCE: IEC 60050-551:1998, 551-15-18]
3.2.6
parallel connection
connection in which two or more converters are connected in such a way that their currents add
3.3 Controllability of converter arms
3.3.1
controllable valve device
a valve device the current path of which is bistably controlled in its conducting direction
[SOURCE: IEC 60050-551:1998, 551-14-03]
3.4 Commutation, quenching and commutation circuitry
3.4.1
commutation
in an electronic power converter the transfer of current from one conducting arm to the next to
conduct in sequence, without interruption of the current, both arms conducting simultaneously
during a finite time interval
[SOURCE: IEC 60050-551:1998, 551-16-01]
3.4.2
quenching
the termination of current flow in an arm without commutation
[SOURCE: IEC 60050-551:1998, 551-16-19]
3.4.3
direct commutation
a commutation between two principal arms without transfer through any auxiliary arms
[SOURCE: IEC 60050-551:1998, 551-16-09]
3.4.4
indirect commutation
a series of commutations from one principal arm to another or back to the original one by
successive commutations via one or more auxiliary arms
[SOURCE: IEC 60050-551:1998, 551-16-10]
3.4.5
line commutation
an external commutation where the commutating voltage is supplied by the line
Note 1 to entry: In the text commutated is used instead of commutation.
[SOURCE: IEC 60050-551:1998, 551-16-12]

– 12 – IEC 62590:2019  IEC 2019
3.4.6
load commutation
an external commutation where the commutating voltage is taken from a load other than the
line
[SOURCE: IEC 60050-551:1998, 551-16-13]
3.4.7
self commutation
a commutation where the commutating voltage is supplied by components within the converter
or the electronic switch
Note 1 to entry: In the text commutated is used instead of commutation
[SOURCE: IEC 60050-551:1998, 551-16-15]
3.5 Commutation characteristics
3.5.1
commutating voltage
the voltage which causes the current to commutate
[SOURCE: IEC 60050-551:1998, 551-16-02]
3.5.2
angle of overlap
u
duration of the commutation interval between a pair of principal arms, expressed in angular
measure, where the two arms carry current
[SOURCE: IEC 60050-551:1998, 551-16-05, modified – “duration of”, “between a pair of
principal arms,” and “,where the two arms carry current” have been added.]
3.5.3
commutating group
a group of principal arms which commutate cyclically among themselves without intermediate
commutation of the current to other principal arms
[SOURCE: IEC 60050-551:1998, 551-16-08]
3.5.4
commutation number
q
number of commutations from one principal arm to another, occurring during one period of the
alternating voltage in each commutating group
[SOURCE: IEC 60050-551:1998, 551-17-03, modified – “during one elementary period” has
been replaced with “occurring during one period of the alternating voltage”.]
3.5.5
pulse number
p
number of non-simultaneous symmetrical direct or indirect commutations from one principal arm
to another, during one period of the alternating voltage
[SOURCE: IEC 60050-551:1998, 551-17-01, modified – “which occur during one elementary
period” has been replaced with “during one period of the alternating voltage”.]

3.5.6
trigger delay angle
α
time expressed in angular measure by which the trigger pulse is delayed with respect to the
reference instant (see Figure 1)
Note 1 to entry: For line, machine or load commutated converters the reference instant is the zero crossing instant
of the commutating voltage.
For AC controllers it is the zero crossing instant of the supply voltage.
For AC controllers with inductive load, the trigger delay angle is the sum of the phase shift and the current delay
angle
[SOURCE: IEC 60050-551:1998, 551-16-33, modified – The end of the definition “in the case
of phase control” has been removed. The note 1 to entry has been changed.]

– 14 – IEC 62590:2019  IEC 2019

Figure 1 – Illustration of angles
3.5.7
trigger advance angle
β
(see Figure 1)
the time expressed in angular measure by which the trigger pulse is advanced with respect to
the reference instant
Note 1 to entry: With line, machine or load commutated converters the reference instant is the zero crossing instant
of the commutating voltage.
[SOURCE: IEC 60050-551:1998, 551-16-34]

3.5.8
extinction angle
γ
time, expressed in angular measure, between the moment when the current of the arm falls to
zero and the moment when the arm is required to withstand steeply rising off-state voltage
3.6 Rated values
3.6.1
rated value
value of a quantity used for specification purposes, established for a specified set of operating
conditions of a component, device, equipment, or system
[SOURCE: IEC 60050-151:2001, 151-16-08]
3.6.2
rated frequency
f
N
frequency on either side of the converter for the conversion of which the converter group is
designed to operate
3.6.3
nominal voltage
U
n
voltage by which a converter is designated
Note 1 to entry: The standardized values of nominal voltages are given in IEC 60850.
3.6.4
rated insulation voltage
U
Nm
rated value of the RMS withstand voltage assigned by the manufacturer to the equipment or to
a part of it, characterizing the specified (long-term) withstand capability of its insulation
Note 1 to entry: Standardized values of rated insulation voltages are given in IEC 62497.
[SOURCE: IEC 60050-312: 2014, 312-06-02, modified – note 1 to entry removed]
3.6.5
rated AC voltage on the supply side of a converter
U
Nv
RMS value of the no-load voltage between vectorially consecutive commutating phase terminals
of a commutating group
3.6.6
rated AC voltage on the traction side of a converter
U
Nt
RMS value of the no-load voltage on the traction side of a frequency converter
3.6.7
rated direct voltage
U
Nd
specified value of the direct voltage between the DC terminals of the converter assembly at
basic direct current
Note 1 to entry: This value is the mean value of the direct voltage.
Note 2 to entry: A converter may have more than one rated voltage or a rated direct voltage range.

– 16 – IEC 62590:2019  IEC 2019
Note 3 to entry: The rated direct voltage of a converter depends on the characteristics of the transformer and a
guaranteed value of rated direct voltage is valid only together with the transformer (see IEC 62589).
3.6.8
basic service current on the supply side of a converter
I
Bv
RMS value of the AC current, containing all harmonics, on the supply side of a converter at
basic current on the DC side
Note 1 to entry: For polyphase equipment, this value is computed from the basic direct current on the basis of
rectangular shaped currents, 120° conducting, of the converter elements. For single phase equipment, the basis of
calculation must be specified.
3.6.9
rated current on the traction side of a frequency converter
I
Nt
RMS value of the AC current on the traction side of a frequency converter under rated conditions
3.6.10
basic current
I
B
mean value of the current for specified load and service conditions
3.6.11
basic direct current
I
Bd
mean value of the direct current for specified load and service conditions
Note 1 to entry: Together with a duty class I is considered as the 1,0 p.u. value, to which other values of I are
Bd d
compared.
3.7 Load capabilities
3.7.1
duty class
tabled representation of current capability and test values for standard design converters in
terms of current values and duration selected to represent a characteristic group of practical
applications
Note 1 to entry: The current values are expressed in per unit of the basic direct current I
B.
3.7.2
load cycle
conventional representation of the current demand to a converter group
Note 1 to entry: The current values are expressed in A or in per unit of I
B.
Note 2 to entry: The load cycle shows the repetitive variation of the loads with time and, hence, the overloads and
underloads the converter group is expected to carry, as well as, for the transformers, the duration and intervals
assumed.
[SOURCE: IEC 60050-881: 2017, 811-28-38 modified – The note 1 to entry has been changed.]
3.7.3
rated DC power
delivered power at working point of basic direct current I
Bd
3.7.4
power efficiency
ratio of the output power to the input power of the converter

3.8 Specific voltages, currents and factors
3.8.1
ideal no-load direct voltage
U
di
theoretical no-load mean direct voltage of a converter, assuming no reduction by phase control,
no voltage drop in the assemblies and no voltage rise at small loads
[SOURCE: IEC 60050-551:1998, 551-17-15, modified – “mean” has been added. “AC/DC” has
been removed. “no threshold voltages of electronic valve devices” has been replaced with “no
voltage drop in the assemblies“.]
3.8.2
controlled ideal no-load direct voltage
U
diα
theoretical no-load direct voltage of an AC/DC converter corresponding to a specified trigger
delay angle assuming no threshold voltages of electronic valve devices and no voltage rise at
small loads
[SOURCE: IEC 60050-551:1998, 551-17-16]
3.8.3
conventional no-load direct voltage
U
d0
mean value of the direct voltage which would be obtained by extrapolating the direct
voltage/current characteristic for continuous direct current back to zero current
Note 1 to entry: U is equal to the sum of U and the no-load voltage drop in the assembly.
di d0
[SOURCE: IEC 60050-551:1998, 551-17-17, modified – “from the region of continuous flow of
direct current to zero current at zero trigger delay angle, i.e. without phase control” has been
replaced with “for continuous direct current back to zero current“.]
3.8.4
real no-load direct voltage
U
d00
actual mean direct voltage at zero direct current
[SOURCE: IEC 60050-551:1998, 551-17-19]
3.8.5
ideal crest no-load voltage
U
iM
no-load voltage between the end terminals of an arm neglecting internal and external voltage
surge and voltage drop in valves
3.8.6
transition current
mean direct current of a converter connection when the direct current of the commutating
groups becomes intermittent when decreasing the current
[SOURCE: IEC 60050-551:1998, 551-17-20, modified – “commutation” has been replaced with
“commutating“]
– 18 – IEC 62590:2019  IEC 2019
3.8.7
direct voltage drop
difference between the conventional no-load direct voltage and the direct voltage at basic direct
current, at the same current delay angle, excluding the correction effect of stabilizing means if
any
Note 1 to entry: The nature of the DC circuit (for example capacitors, voltage sources) can affect the voltage drop
significantly. Where this is the case, special consideration is required.
3.8.8
total power factor
λ
active power
λ=
apparent power
3.8.9
power factor of the fundamental wave or displacement factor
cos ϕ
active power of the fundamental wave
cosϕ =
apparent power of the fundamental wave

3.9 Definitions related to virtual junction temperature
3.9.1
thermal resistance
R
th
quotient of the difference between the virtual temperature of the device and the temperature of
a stated external reference point, by the steady state power dissipation in the device
[SOURCE: IEC 60050-521:2002, 521-05-13]
3.9.2
transient thermal impedance
Z
th
quotient of the variation of the temperature difference, reached at the end of a time interval
between the virtual junction temperature and the temperature at a specified external reference
point and the step function change of power dissipation at the beginning of the same time
interval causing the change of temperature
Note 1 to entry: The transient thermal impedance is given in a characteristic curve as a function of the time interval.
3.9.3
virtual junction temperature
Θ
j
calculated temperature within the semiconductor material which is based on a simplified
representation of the thermal and electrical behaviour of a semiconductor device
3.10 Cooling
3.10.1
cooling medium
liquid (for example water) or gas (for example air) which removes the heat from the equipment

3.10.2
heat transfer agent
liquid (for example water) or gas (for example air) within the equipment to transfer the heat from
its source to a heat exchanger from where the heat is removed by the cooling medium
3.10.3
direct cooling
method of cooling by which the cooling medium is in direct contact with the parts of the
equipment to be cooled, i.e. no heat transfer agent is used
3.10.4
indirect cooling
method of cooling in which a heat transfer agent is used to transfer heat from the part to be
cooled to the cooling medium
3.10.5
natural circulation
convection
method of circulating the cooling medium or heat transfer agent which uses the change of
volumetric mass (density) with temperature
3.10.6
forced circulation
forced cooling
method of circulating the cooling medium or heat transfer agent by means of blower(s), fan(s)
or pump(s)
3.10.7
thermal equilibrium
steady-state temperature condition reached by a component of a converter under specified
conditions of load and cooling
Note 1 to entry: The steady-state temperatures are in general different for different components. The times
necessary to establish steady-state are also different and proportional to the thermal time constants.
3.11 Electromagnetic compatibility and harmonic distortion
3.11.1
electrical disturbance
any variation of an electrical quantity, beyond specified limits, which can be the cause of a loss
of performance or an interruption of service or damage
3.11.2
immunity level
specified value of an electrical disturbance below which a converter is designed to me
...

IEC 62590 ®
Edition 2.0 2019-08
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Railway applications – Fixed installations – Electronic power converters for
substations
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IEC 62590 ®
Edition 2.0 2019-08
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Railway applications – Fixed installations – Electronic power converters for

substations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 45.060.01 ISBN 978-2-8322-7357-9

– 2 – IEC 62590:2019 RLV  IEC 2019
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
3.1 Semiconductor devices and combinations . 10
3.2 Arms and connections . 10
3.3 Controllability of converter arms and quadrants of operation . 12
3.4 Commutation, quenching and commutation circuitry . 12
3.5 Commutation characteristics . 13
3.6 Rated values . 17
3.7 Load capabilities . 18
3.8 Specific voltages, currents and factors . 19
3.9 Definitions related to virtual junction temperature . 21
3.10 Cooling . 21
3.11 Electromagnetic compatibility and harmonic distortion . 22
4 Symbols . 22
5 Operation of semiconductor power equipment and valve devices . 23
5.1 Classification of traction supply power converters and valves . 23
5.1.1 Types of traction supply power converters . 23
5.1.2 Purpose of conversion . 24
5.1.3 Classification of semiconductor valve devices . 24
5.2 Basic calculation factors for line commutated converters . 25
5.2.1 Voltage . 25
5.2.2 Voltage characteristics and transition current . 25
6 Service conditions . 26
6.1 Code of identification of cooling method . 26
6.1.1 Letter symbols to be used . 26
6.1.2 Arrangement of letter symbols . 27
6.2 Environmental conditions . 27
6.2.1 Ambient air circulation . 27
6.2.2 Normal service conditions . 28
6.2.3 Special service conditions . 29
6.3 Electrical service conditions . 29
6.3.1 General . 29
6.3.2 Limiting values as basis of rating . 29
6.3.3 DC traction supply voltage . 31
7 Converter equipment and assemblies . 31
7.1 Losses and efficiency . 31
7.1.1 General . 31
7.1.2 Included losses . 31
7.2 Power factor . 31
Direct voltage harmonic content .
7.3 Electromagnetic compatibility (EMC) . 32
7.4 Rated values for converters . 32

7.4.1 General . 32
7.4.2 Current values . 33
7.4.3 Capability for unsymmetrical load of a 12-pulse converter in parallel
connection . 35
7.4.4 Semiconductor device failure conditions . 35
7.5 Mechanical characteristics . 35
7.5.1 General . 35
7.5.2 Earthing . 36
7.5.3 Degree of protection . 36
7.6 Insulation coordination . 36
7.7 Specifics of line commutated rectifiers . 37
7.7.1 Electrical connections . 37
7.7.2 Calculation factors . 38
7.7.3 Direct voltage harmonic content . 39
8 Tests . 39
8.1 General . 39
8.1.1 Overview . 39
8.1.2 Performance of tests . 39
8.1.3 Test schedule . 40
8.2 Test specifications . 40
8.2.1 Insulation tests . 40
8.2.2 Light load functional test . 43
8.2.3 Load test . 43
8.2.4 Power loss determination . 43
8.2.5 Temperature-rise test . 43
8.2.6 Checking of auxiliary devices . 45
8.2.7 Checking of the properties of the control equipment . 45
8.2.8 Checking of the protective devices . 45
8.2.9 Short-time withstand current test . 45
8.2.10 EMC test . 46
8.2.11 Additional tests . 46
9 Marking . 46
9.1 Rating plate . 46
9.2 Main circuit terminals . 47
Annex A (informative) Information required . 48
A.1 General . 48
A.2 Diode rectifiers . 48
A.2.1 Procurement specification . 48
A.2.2 Supplier's tender specification . 49
A.2.3 Information and data to be given by the supplier during the delivery
stage . 49
A.3 Controlled converters and inverters. 50
A.3.1 Procurement specification . 50
A.3.2 Supplier's tender specification . 51
A.4 Frequency converters (direct and DC link converters) . 51
A.4.1 Procurement specification . 51
A.4.2 Supplier's tender specification . 52
A.5 DC converters . 53
A.5.1 Procurement specification . 53

– 4 – IEC 62590:2019 RLV  IEC 2019
A.5.2 Supplier’s tender specification . 54
Annex B (informative) Determination of the current capability through calculation of
the virtual junction temperature . 56
B.1 General . 56
B.2 Approximation of the shape of power pulses applied to the semiconductor
device . 56
B.3 Superposition method for the calculation of temperature . 57
B.4 Calculation of virtual junction temperature for continuous load . 58
B.4.1 General . 58
B.4.2 Calculation of mean value of virtual junction temperature . 58
B.4.3 Calculation of maximum instantaneous virtual junction temperature . 58
B.5 Calculation of virtual junction temperature for cyclic loads . 59
B.6 Examples for typical applications . 60
Annex C (informative) Index of definitions . 62
Bibliography . 64

Figure 1 – Illustration of angles . 16
Figure 2 – Voltage drop regulation . 26
Figure 3 – AC voltage waveform . 30
Figure B.1 – Approximation of the shape of power pulses . 57
Figure B.2 – Calculation of the virtual junction temperature for continuous load . 58
Figure B.3 – Calculation of the virtual junction temperature for cyclic load . 59

Table 1 – Letter symbols for cooling mediums and heat transfer agents . 26
Table 2 – Letter symbols for methods of circulation . 26
Table 3 – Standardized duty classes . 33
Table 4 – Semiconductor device failure conditions . 35
Table 5 – Insulation levels for AC/DC and DC converters . 37
Table 6 – Connections and calculation factors for line commutated converters . 37
Table 7 – Summary of tests . 40
Table 8 – Insulation levels for AC/DC and DC converters . 42
Table B.1 – Examples for typical applications . 60

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RAILWAY APPLICATIONS – FIXED INSTALLATIONS –
ELECTRONIC POWER CONVERTERS FOR SUBSTATIONS

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
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes
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– 6 – IEC 62590:2019 RLV  IEC 2019
International Standard IEC 62590 has been prepared by IEC technical committee 9: Electrical
equipment and systems for railways.
This standard is based on EN 50328.
This second edition cancels and replaces the first edition published in 2010. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Incorporation of DC converters.
b) Correction of the clearances and withstand voltages due to erroneous use of PD in former
edition.
c) Adaption to current ISO/IEC directive part 2, adaption of structure, adaption of vocabulary,
removal of unused term and abbreviations.
The text of this standard is based on the following documents:
FDIS Report on voting
9/2502/FDIS 9/2516/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 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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

INTRODUCTION
Semiconductor converters for traction power supply differ from other converters for industrial
use due to special electrical service conditions and due to the large range of load variation and
the peculiar characteristics of the load.
For these reasons IEC 60146-1-1 does not fully cover the requirements of railway applications
and the decision was taken to have a specific standard for this use.
Converter transformers for fixed installations of railway applications are covered by EN 50329
IEC 62695.
Harmonization of the rated values and tests of the whole converter group are covered by
IEC 62589.
– 8 – IEC 62590:2019 RLV  IEC 2019
RAILWAY APPLICATIONS – FIXED INSTALLATIONS –
ELECTRONIC POWER CONVERTERS FOR SUBSTATIONS

1 Scope
This document specifies the requirements for the performance of all fixed installations electronic
power converters, using controllable and/or non-controllable electronic valves, intended for
traction power supply.
The devices can be controlled by means of current, voltage or light. Non-bistable devices are
assumed to be operated in the switched mode.
This document applies to fixed installations of the following electric traction systems:
• railways,
• guided mass transport systems such as: tramways, light rail systems, elevated and
underground railways, mountain railways, trolleybusses.
This document does not apply to:
• cranes, transportable platforms and similar transportation equipment on rails,
• suspended cable cars,
• funicular railways.
This document applies to diode rectifiers, controlled rectifiers, DC converters, inverters and
frequency converters.
The equipment covered in this document is the converter itself.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 60050-551:1998, International Electrotechnical Vocabulary (IEV) – Part 551: Power
Electronics
IEC 60050-811:19912017, International electrotechnical vocabulary – Part 811: Electric traction
IEC 60146 (all parts), Semiconductor convertors
IEC TR 60146-1-2:19912011, Semiconductor converters – General requirements and line
commutated converters – Part 1-2: Application guide
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60721 (all parts), Classification of environmental conditions
IEC 60721-3-3:1994, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 3: Stationary use at

weatherprotected locations
AMD1:1995
AMD2:1996
IEC 60721-3-4:1995, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 4: Stationary use at non-
weatherprotected locations
AMD1:1996
IEC 60850:20072014, Railway applications – Supply voltages of traction systems
IEC 61000-2-4:2002, Electromagnetic compatibility (EMC) – Part 2-4: Environment –
Compatibility levels in industrial plants for low-frequency conducted disturbances
IEC 61000-2-12:2003, Electromagnetic compatibility (EMC) – Part 2-12: Environment –
Compatibility levels for low-frequency conducted disturbances and signalling in public medium-
voltage power supply systems
IEC 61992-7-1:2006, Railway applications – Fixed installations – DC switchgear – Part 7-1:
Measurement, control and protection devices for specific use in DC traction systems –
Application guide
IEC 62236 (all parts), Railway applications – Electromagnetic compatibility
IEC 62236-5:20082018, Railway applications – Electromagnetic compatibility – Part 5:
Emission and immunity of fixed power supply installations and apparatus
IEC 62497-1:2010, Railway applications – Insulation coordination – Part 1: Basic requirements
– Clearances and creepage distances for all electrical and electronic equipment
EN 50329:2003, Railway applications – Fixed installations – Traction transformers
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. In this standard,
IEV definitions are used wherever possible, particularly those in IEC 60050-551.
The policy adopted is as follows:
a) when a suitable IEV definition exists, the term and the reference are given without repeating
the text;
b) when an existing IEV definition needs amplification or additional information, the term, the
reference and the additional text are given;
c) when no IEV definition exists, the term and the text are given.
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 An alphabetical index is given in Annex C.

– 10 – IEC 62590:2019 RLV  IEC 2019
3.1 Semiconductor devices and combinations
3.1.1
semiconductor device
device whose essential characteristics are due to the flow of charge carriers within a
semiconductor
[SOURCE: IEC 60050-521: 2002, 521-04-01, modified – note omitted]
3.1.2
(valve device) stack
a single structure of one or more electronic valve devices with its (their) associated mounting(s)
and auxiliaries if any
[SOURCE: IEC 60050-551:1998, 551-14-12]
3.1.3
(valve device) assembly
an electrically and mechanically combined assembly of electronic valve devices or stacks,
complete with all its connections and auxiliaries in its own mechanical structure
[SOURCE: IEC 60050-551:1998, 551-14-13]
3.1.4
electronic power converter
operative unit for power conversion comprising one or more assemblies of semiconductor
devices
Note 1 to entry: The transformers are described in IEC 62695
[SOURCE: IEC 60050-551:1998, 551-12-01, modified – “electronic” has been omitted.
“electronic valve devices, transformers and filters if necessary and auxiliaries if any” has been
replaced with “assemblies of semiconductor devices”. The note 1 to entry has been omitted.]
3.1.5
trigger equipment (gating equipment)
equipment which provides suitable trigger pulses from a control signal for controllable valve
devices in a converter or power switch including timing or phase shifting circuits, pulse
generating circuits and usually power supply circuits
3.1.6
system control equipment
equipment associated with a converter equipment or system which performs automatic
adjustment of the output characteristics as a function of a controlled quantity
3.2 Arms and connections
3.2.1
(valve) arm
a part of the circuit of an electronic power converter or switch bounded by any two AC or DC
terminals and including one or more simultaneously conducting electronic valve devices
connected together and other components if any
[SOURCE: IEC 60050-551:1998, 551-15-01]
3.2.2
principal arm
a valve arm involved in the major transfer of power from one side of the converter or electronic
switch to the other
Note 1 to entry: Depending on the mode of operation a principal arm may act as an auxiliary arm or vice versa.
[SOURCE: IEC 60050-551:1998, 551-15-02]
3.2.3
converter connection
the electrical arrangement of valve arms and other components essential for the function of the
main power circuit of a converter
[SOURCE: IEC 60050-551:1998, 551-15-10]
3.2.4
basic converter connection
[IEV 551-15-11]
3.2.5
single-way connection (of a converter)
[IEV 551-15-12]
3.2.6
double-way connection (of a converter)
[IEV 551-15-13]
3.2.4
uniform connection
a connection with either all principal arms controllable or all principal arms non-controllable
[SOURCE: IEC 60050-551:1998, 551-15-15]
3.2.5
non-uniform connection
a connection with both controllable and non-controllable principal arms
[SOURCE: IEC 60050-551:1998, 551-15-18]
3.2.9
series connection
connection in which two or more converters are connected in such a way that their voltages add
3.2.10
boost and buck connection
series connection in which the converters are controlled independently
[IEV 551-15-21, modified]
3.2.6
parallel connection
connection in which two or more converters are connected in such a way that their currents add

– 12 – IEC 62590:2019 RLV  IEC 2019
3.3 Controllability of converter arms and quadrants of operation
3.3.1
controllable arm
converter arm including controllable semiconductor element(s) as valve device(s)
3.3.2
non-controllable arm
converter arm including non-controllable semiconductor element(s) as valve device(s)
3.3.3
quadrant of operation (on the d.c. side)
quadrant of the voltage current plane defined by the d.c. voltage polarity and the current
direction
3.3.4
one quadrant converter
[IEV 551-12-34]
3.3.5
two quadrant (single) converter
[IEV 551-12-35]
3.3.6
four quadrant (double) converter
[IEV 551-12-36]
3.3.7
reversible converter
[IEV 551-12-37]
3.3.8
single converter
[IEV 551-12-38]
3.3.9
double converter
[IEV 551-12-39]
3.3.10
converter section of a double converter
[IEV 551-12-40]
3.3.1
controllable valve device
a valve device the current path of which is bistably controlled in its conducting direction
[SOURCE: IEC 60050-551:1998, 551-14-03]
3.4 Commutation, quenching and commutation circuitry
3.4.1
commutation
transfer of current from one conducting arm to the next to conduct in sequence, without
interruption of the d.c. current. During a finite interval of time both arms are conducting
simultaneously
in an electronic power converter the transfer of current from one conducting arm to the next to
conduct in sequence, without interruption of the current, both arms conducting simultaneously
during a finite time interval
[SOURCE: IEC 60050-551:1998, 551-16-01]
3.4.2
quenching
the termination of current flow in an arm without commutation
[SOURCE: IEC 60050-551:1998, 551-16-19]
3.4.3
direct commutation
a commutation between two principal arms without transfer through any auxiliary arms
[SOURCE: IEC 60050-551:1998, 551-16-09]
3.4.4
indirect commutation
a series of commutations from one principal arm to another or back to the original one by
successive commutations via one or more auxiliary arms
[SOURCE: IEC 60050-551:1998, 551-16-10]
3.4.5
external commutation
[IEV 551-16-11]
3.4.5
line commutation
an external commutation where the commutating voltage is supplied by the line
Note 1 to entry: In the text commutated is used instead of commutation.
[SOURCE: IEC 60050-551:1998, 551-16-12]
3.4.6
load commutation
an external commutation where the commutating voltage is taken from a load other than the
line
[SOURCE: IEC 60050-551:1998, 551-16-13]
3.4.7
self commutation
a commutation where the commutating voltage is supplied by components within the converter
or the electronic switch
Note 1 to entry: In the text commutated is used instead of commutation
[SOURCE: IEC 60050-551:1998, 551-16-15]
3.5 Commutation characteristics
3.5.1
commutation circuit
[IEV 551-16-03]
– 14 – IEC 62590:2019 RLV  IEC 2019
3.5.1
commutating voltage
the voltage which causes the current to commutate
[SOURCE: IEC 60050-551:1998, 551-16-02]
3.5.3
commutation inductance
total inductance included in the commutation circuit, in series with the commutating voltage
[IEV 551-16-07, modified]
NOTE For line or machine commutated converters the commutation reactance is the impedance of the commutation
inductance at the fundamental frequency.
3.5.2
angle of overlap
u
duration of the commutation interval between a pair of principal arms, expressed in angular
measure, where the two arms carry current
[SOURCE: IEC 60050-551:1998, 551-16-05, modified – “duration of”, “between a pair of
principal arms,” and “,where the two arms carry current” have been added.]
3.5.5
commutation notch
periodic voltage transient that can appear in the a.c. voltage of a line or machine-commutated
converter due to commutation
[IEV 551-16-06, modified]
3.5.6
commutation repetitive transient
voltage oscillation associated with the commutation notch
3.5.3
commutating group
a group of principal arms which commutate cyclically among themselves without intermediate
commutation of the current to other principal arms
[SOURCE: IEC 60050-551:1998, 551-16-08]
3.5.4
commutation number
q
number of commutations from one principal arm to another, occurring during one period of the
alternating voltage in each commutating group
[SOURCE: IEC 60050-551:1998, 551-17-03, modified – “during one elementary period” has
been replaced with “occurring during one period of the alternating voltage”.]
3.5.5
pulse number
p
number of non-simultaneous symmetrical direct or indirect commutations from one principal arm
to another, during one period of the alternating voltage
[SOURCE: IEC 60050-551:1998, 551-17-01, modified – “which occur during one elementary
period” has been replaced with “during one period of the alternating voltage”.]

3.5.6
trigger delay angle
α
time expressed in angular measure by which the trigger pulse is delayed with respect to the
reference instant (see Figure 1)
Note 1 to entry: For line, machine or load commutated converters the reference instant is the zero crossing instant
of the commutating voltage.
For AC controllers it is the zero crossing instant of the supply voltage.
For AC controllers with inductive load, the trigger delay angle is the sum of the phase shift and the current delay
angle
[SOURCE: IEC 60050-551:1998, 551-16-33, modified – The end of the definition “in the case
of phase control” has been removed. The note 1 to entry has been changed.]

– 16 – IEC 62590:2019 RLV  IEC 2019

Figure 1 – Illustration of angles
3.5.7
trigger advance angle
β
(see Figure 1)
the time expressed in angular measure by which the trigger pulse is advanced with respect to
the reference instant
Note 1 to entry: With line, machine or load commutated converters the reference instant is the zero crossing instant
of the commutating voltage.
[SOURCE: IEC 60050-551:1998, 551-16-34]

3.5.12
inherent delay angle α
p
delay angle which occurs in some converter connections under certain operating conditions
even if no phase control is applied
[IEV 551-16-35, modified]
3.5.8
extinction angle
γ
time, expressed in angular measure, between the moment when the current of the arm falls to
zero and the moment when the arm is required to withstand steeply rising off-state voltage
3.6 Rated values
3.6.1
rated value
numerical value for the electrical, thermal, mechanical and environmental rating assigned to
the quantities which define the operation of a converter group in the conditions specified in
accordance with this Standard and on which the supplier’s guarantees and tests are based
value of a quantity used for specification purposes, established for a specified set of operating
conditions of a component, device, equipment, or system
[SOURCE: IEC 60050-151:2001, 151-16-08]
3.6.2
rated frequency
f
N
frequency on either side of the converter for the conversion of which the converter group is
designed to operate
3.6.3
nominal voltage
U
n
voltage by which a converter is designated
Note 1 to entry: The standardized values of nominal voltages are given in IEC 60850.
3.6.4
rated insulation voltage
U
Nm
rated value of the RMS withstand voltage value assigned by the manufacturer to the equipment
or to a part of it, characterizing the specified permanent (long-term) withstand capability of its
insulation
Note 1 to entry: Standardized values of rated insulation voltages are given in IEC 62497.
[SOURCE: IEC 60050-312: 2014, 312-06-02, modified – note 1 to entry removed]
3.6.5
rated AC voltage on the supply side of a converter
U
Nv
RMS value of the no-load voltage between vectorially consecutive commutating phase terminals
of a commutating group
– 18 – IEC 62590:2019 RLV  IEC 2019
3.6.6
rated AC voltage on the traction side of a converter
U
Nt
RMS value of the no-load voltage on the traction side of a frequency converter
3.6.7
rated direct voltage
U
Nd
specified value of the direct voltage between the DC terminals of the converter assembly at
basic direct current
Note 1 to entry: This value is the mean value of the direct voltage.
Note 2 to entry: A converter may have more than one rated voltage or a rated direct voltage range.
Note 3 to entry: The rated direct voltage of a converter depends on the characteristics of the transformer and a
guaranteed value of rated direct voltage is valid only together with the transformer (see IEC 62589).
3.6.8
basic service current on the supply side of a converter
I
Bv
RMS value of the AC current, containing all harmonics, on the supply side of a converter at
basic current on the DC side
Note 1 to entry: For polyphase equipment, this value is computed from the basic direct current on the basis of
rectangular shaped currents, 120° conducting, of the converter elements. For single phase equipment, the basis of
calculation must be specified.
3.6.9
rated current on the traction side of a frequency converter
I
Nt
RMS value of the AC current on the traction side of a frequency converter under rated conditions
3.6.10
basic current
I
B
mean value of the current for specified load and service conditions
3.6.11
basic direct current
I
Bd
mean value of the direct current for specified load and service conditions
Note 1 to entry: Together with a duty class I is considered as the 1,0 p.u. value, to which other values of I are
Bd d
compared.
3.7 Load capabilities
3.7.1
duty class
tabled representation of current capability and test values for standard design converters in
terms of current values and duration selected to represent a characteristic group of practical
applications. The current values are expressed in per unit of the basic direct current I
Bd
Note 1 to entry: The current values are expressed in per unit of the basic direct current I
B.
3.7.2
load cycle
representation of the conventional current demand to a special design converter showing the
repetitive variation of the load within a specified time period. The current values are expressed
in A or in per unit of I
bd
conventional representation of the current demand to a converter group

Note 1 to entry: The current values are expressed in A or in per unit of I
B.
Note 2 to entry: The load cycle shows the repetitive variation of the loads with time and, hence, the overloads and
underloads the converter group is expected to carry, as well as, for the transformers, the duration and intervals
assumed.
[SOURCE: IEC 60050-881: 2017, 811-28-38 modified – The note 1 to entry has been changed.]
3.7.3
rated DC power
product of the nominald.c. voltage U and the basic direct current I
n bd
delivered power at working point of basic direct current I
Bd
3.7.4
power efficiency
ratio of the output power to the input power of the converter
3.8 Specific voltages, currents and factors
3.8.1
ideal no-load direct voltage
U
di
theoretical no-load mean direct voltage of a converter, assuming no reduction by phase control,
no voltage drop in the assemblies and no voltage rise at small loads
[SOURCE: IEC 60050-551:1998, 551-17-15, modified – “mean” has been added. “AC/DC” has
been removed. “no threshold voltages of electronic valve devices” has been replaced with “no
voltage drop in the assemblies“.]
3.8.2
controlled ideal no-load direct voltage
U
diα
theoretical no-load mean direct voltage of a converter, when the direct voltage is reduced by
phase control, assuming no voltage drop in the assemblies and no voltage rise at small loads
theoretical no-load direct voltage of an AC/DC converter corresponding to a specified trigger
delay angle assuming no threshold voltages of electronic valve devices and no voltage rise at
small loads
[SOURCE: IEC 60050-551:1998, 551-17-16, modified]
3.8.3
conventional no-load direct voltage
U
d0
mean value of the direct
...