IEC 60700-1:2015
(Main)Thyristor valves for high voltage direct current (HVDC) power transmission - Part 1: Electrical testing
Thyristor valves for high voltage direct current (HVDC) power transmission - Part 1: Electrical testing
IEC 60700-1:2015 applies to thyristor valves with metal oxide surge arresters directly connected between the valve terminals, for use in a line commutated converter for high voltage d.c. power transmission or as part of a back-to-back link. It is restricted to electrical type and production tests. The tests specified in this standard are based on air insulated valves. For other types of valves, the test requirements and acceptance criteria can be agreed. This edition includes the following significant technical changes with respect to the previous edition.
a) Definitions of terms "redundant thyristor levels", "thyristor level", "valve section" have been changed for clarification.
b) The notes were added to test requirements of dielectric d.c. voltage tests for valve support, MVU, valve, specifying that before repeating the test with opposite polarity, the tested object may be short-circuited and earthed for several hours. The same procedure may be followed at the end of the d.c. voltage test.
c) Table 1 on thyristor level faults permitted during type tests was supplemented.
d) The alternative MVU dielectric test method was added.
e) It was specified that production tests may include routine tests as well as sample tests.
f) It was added into test requirements for periodic firing and extinction tests that a scaling factor for tests shall be applied when testing with valve sections.
The contents of the corrigendum of January 2017 have been included in this copy.
Valves à thyristors pour le transport d'énergie en courant continu à haute tension (CCHT) - Partie 1: Essais électriques
IEC 60700-1:2015 s'applique aux valves à thyristors équipées de parafoudres à oxyde métallique directement connectés entre les bornes des valves, qui sont destinées à être utilisées au niveau d'un convertisseur commuté par le réseau pour le transport d'énergie en courant continu à haute tension ou dans une liaison dos à dos. Elle est limitée aux essais de type électriques et de série. Les essais spécifiés dans la présente norme sont basés sur des valves isolées par l'air. Pour d'autres types de valves, les exigences d'essai et les critères d'acceptation peuvent faire l'objet d'un accord. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente.
a) Les définitions des termes "niveaux de thyristors redondants", "niveau de thyristor", "section de valve" ont été modifiées dans un souci de clarification.
b) Des notes ont été ajoutées aux exigences des essais diélectriques sur support de valve sous tension continue, UVM, spécifiant qu'avant de répéter l'essai avec la polarité opposée, l'objet d'essai peut être court-circuité et mis à la terre pendant plusieurs heures. La même procédure peut être suivie à l'issue de l'essai sous tension continue.
c) Le Tableau 1 sur les défauts de niveaux de thyristors autorisés au cours des essais de type a été complété.
d) La méthode alternative pour les essais diélectriques UVM a été ajoutée.
e) Il a été spécifié que les essais de série peuvent inclure des essais individuels de série ainsi que des essais sur prélèvement.
f) Il a été ajouté dans les exigences pour les essais d'allumage et d'extinction périodiques qu'un facteur d'échelle pour les essais doit être appliqué lors des essais sur les sections de valve.
Le contenu du corrigendum de janvier 2017 a été pris en considération dans cet exemplaire.
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Standards Content (Sample)
IEC 60700-1 ®
Edition 2.0 2015-07
REDLINE VERSION
INTERNATIONAL
STANDARD
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Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
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IEC 60700-1 ®
Edition 2.0 2015-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.200 ISBN 978-2-8322-2826-5
– 2 – IEC 60700-1:2015 RLV © IEC 2015
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions. 7
3.1 Insulation co-ordination terms . 8
3.2 Valve construction terms . 9
3.3 Terms related to type tests . 10
3.4 Terms related to production tests . 10
4 General requirements . 10
4.1 Guidelines for the performance of type tests . 10
4.1.1 Evidence in lieu . 10
4.1.2 Test object . 10
4.1.3 Sequence of tests . 10
4.1.4 Test procedures . 11
4.1.5 Ambient temperature for testing . 11
4.1.6 Frequency for testing . 11
4.1.7 Test reports . 11
4.2 Atmospheric correction . 11
4.3 Treatment of redundancy . 11
4.3.1 Dielectric tests . 11
4.3.2 Operational tests . 12
4.4 Criteria for successful type testing . 12
4.4.1 General . 12
4.4.2 Criteria applicable to thyristor levels . 12
4.4.3 Criteria applicable to the valve as a whole . 13
5 List of type tests . 13
6 Dielectric tests on valve support . 14
6.1 Purpose of tests . 14
6.2 Test object . 14
6.3 Test requirements . 15
6.3.1 General . 15
6.3.2 Valve support d.c. voltage test . 15
6.3.3 Valve support a.c. voltage test . 15
6.3.4 Valve support switching impulse test . 16
6.3.5 Valve support lightning impulse test . 16
7 Dielectric tests for multiple valve units (MVU) . 16
7.1 Purpose of tests . 16
7.2 Test object . 17
7.3 Test requirements . 17
7.3.1 MVU d.c. voltage test to earth . 17
7.3.2 MVU a.c. voltage test . 18
7.3.3 MVU switching impulse test . 18
7.3.4 MVU lightning impulse test . 19
8 Dielectric tests between valve terminals . 20
8.1 Purpose of tests . 20
8.2 Test object . 20
8.3 Test requirements . 20
8.3.1 Valve d.c. voltage test . 20
8.3.2 Valve a.c. voltage test . 21
8.3.3 Valve impulse tests (general) . 22
8.3.4 Valve switching impulse test . 23
8.3.5 Valve lightning impulse test . 23
8.3.6 Valve steep front impulse test . 24
8.4 Valve non-periodic firing test . 24
8.4.1 Purpose of test . 24
8.4.2 Test object . 24
8.4.3 Test requirements . 25
9 Periodic firing and extinction tests . 26
9.1 Purpose of tests . 26
9.2 Test object . 26
9.3 Test requirements . 26
9.3.1 General . 26
9.3.2 Maximum continuous operating duty tests . 27
9.3.3 Maximum temporary operating duty test (a = 90°) . 29
9.3.4 Minimum a.c. voltage tests . 30
9.3.5 Temporary undervoltage test . 31
9.3.6 Intermittent direct current tests . 32
10 Tests with transient forward voltage during the recovery period . 32
10.1 Purpose of tests . 32
10.2 Test object . 32
10.3 Test requirements . 33
11 Valve fault current tests . 34
11.1 Purpose of tests . 34
11.2 Test object . 34
11.3 Test requirements . 34
11.3.1 General . 34
11.3.2 One-loop fault current test with re-applied forward voltage . 35
11.3.3 Multiple-loop fault current test without re-applied forward voltage . 36
12 Tests for valve insensitivity to electromagnetic disturbance . 36
12.1 Purpose of tests . 36
12.2 Test object . 37
12.3 Test requirements . 37
12.3.1 General . 37
12.3.2 Approach one . 37
12.3.3 Approach two . 37
12.3.4 Acceptance criteria . 38
13 Testing of special features and fault tolerance . 38
13.1 Purpose of tests . 38
13.1.1 General . 38
13.1.2 Circuits to facilitate the proper control, protection and monitoring of the
valve . 38
13.1.3 Features included in the valve to provide fault tolerance . 38
13.2 Test object . 39
13.3 Test requirements . 39
– 4 – IEC 60700-1:2015 RLV © IEC 2015
14 Production tests . 39
14.1 General . 39
14.2 Purpose of tests . 39
14.3 Test object . 39
14.4 Test requirements . 39
14.5 Production test objectives Routine test – minimum requirements . 40
14.5.1 Visual inspection . 40
14.5.2 Connection check . 40
14.5.3 Voltage-grading circuit check . 40
14.5.4 Voltage withstand check . 40
14.5.5 Partial discharge tests . 40
14.5.6 Check of auxiliaries . 40
14.5.7 Firing check . 40
14.5.8 Pressure test . 40
15 Method for loss determination . 40
16 Presentation of type test results . 41
Annex A (normative) Test safety factors . 42
A.1 General . 42
A.2 Test safety factors for dielectric tests . 42
A.2.1 Impulse tests . 42
A.2.2 AC and d.c. temporary and long-term voltage tests . 45
A.3 Test safety factors for operational tests . 45
Annex B (normative) Partial discharge measurements . 46
B.1 Measurement of partial discharge . 46
B.2 Partial discharge during a.c. tests . 46
B.3 Partial discharge during d.c. tests . 46
B.4 Composite a.c. plus d.c. voltage stress . 47
Annex C (informative) Fault tolerance capability………………………………………………………
Figure 1 – Steep front impulse test voltage . 8
Table 1 – Thyristor level faults permitted during type tests . 13
Table 2 – List of type tests . 14
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THYRISTOR VALVES FOR HIGH VOLTAGE DIRECT
CURRENT (HVDC) POWER TRANSMISSION –
Part 1: Electrical testing
FOREWORD
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– 6 – IEC 60700-1:2015 RLV © IEC 2015
International Standard IEC 60700-1 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 second edition cancels and replaces the first edition published in 1998, its Amendment
1:2003 and its Amendment 2: 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition.
a) Definitions of terms “redundant thyristor levels”, “thyristor level”, “valve section” have been
changed for clarification.
b) The notes were added to test requirements of dielectric d.c. voltage tests for valve support,
MVU, valve, specifying that before repeating the test with opposite polarity, the tested
object may be short-circuited and earthed for several hours. The same procedure may be
followed at the end of the d.c. voltage test.
c) Table 1 on thyristor level faults permitted during type tests was supplemented.
d) The alternative MVU dielectric test method was added.
e) It was specified that production tests may include routine tests as well as sample tests.
f) It was added into test requirements for periodic firing and extinction tests that a scaling
factor for tests shall be applied when testing with valve sections.
The text of this standard is based on the following documents:
CDV Report on voting
22F/341/CDV 22F/351A/RVC
Full information on the voting for the approval of this 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.
A list of all parts in the IEC 60700 series, published under the general title Thyristor valves for
high voltage direct current (HVDC) power transmission, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC website 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.
The contents of the corrigendum of January 2017 have been included in this copy.
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 publication using a colour printer.
THYRISTOR VALVES FOR HIGH VOLTAGE DIRECT
CURRENT (HVDC) POWER TRANSMISSION –
Part 1: Electrical testing
1 Scope
This part of IEC 60700 applies to thyristor valves with metal oxide surge arresters directly
connected between the valve terminals, for use in a line commutated converter for high voltage
d.c. power transmission or as part of a back-to-back link. It is restricted to electrical type and
production tests.
The tests specified in this standard are based on air insulated valves. For other types of valves,
the test requirements and acceptance criteria must can be agreed.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
IEC 60060, High-voltage test techniques
IEC 60060-1:1989, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60071-1:1993, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60099 (all parts), Surge arresters
IEC 60270:1981, High-voltage test techniques – Partial discharge measurements
IEC 61803:1999, Determination of power losses in high-voltage direct current (HVDC)
converter stations
IEC 61803:1999/AMD1:2010
ISO/IEC Guide 25:1990, General requirements for the technical competence of calibration and
testing laboratories
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
___________
There exists a consolidated edition 1.1 (2011) that comprises IEC 61803:1999 and its Amendment 1:2010.
Withdrawn.
– 8 – IEC 60700-1:2015 RLV © IEC 2015
3.1 Insulation co-ordination terms
3.1.1
test withstand voltage
value of a test voltage of standard waveshape at which a new valve, with unimpaired integrity,
does not show any disruptive discharge and meets all other acceptance criteria specified for
the particular test, when subjected to a specified number of applications or a specified duration
of the test voltage, under specified conditions
3.1.2
steep front impulse
fast-front voltage impulse whose time to peak is less than that of a standard lightning impulse
but not less than that of a very-fast-front voltage as defined in IEC 60071-1.
Note 1 to entry: For this standard, the steep front impulse voltage for test purposes is as shown in Figure 1.
Steepness S
Peak value U
0,2 T
0,5 U
T
Time
T
IEC
Key
U specified peak value of steep front impulse test voltage (kV)
S specified steepness of steep front impulse test voltage (kV/µs)
U
T virtual front time = (µs)
S
The following conditions shall be satisfied:
a) The peak value of the recorded test voltage shall be U ± 3 %. This tolerance is the same as that in IEC 60060
for standard lightning impulse.
b) Over a voltage excursion of not less than 0,6 U, the rising portion of the recorded test voltage shall be entirely
contained between two parallel lines of steepness S and separation 0,2 T
1.
c) The value of the test voltage at T shall not be lower than 0,5 U. T is defined as the time interval between the
2 2
origin and the instant when the voltage has decreased to half the peak value of the waveform which is obtained
from system study. However, it shall be assured that an unintentional du/dt switching of the thyristors can be
adequately detected.
Figure 1 – Steep front impulse test voltage
0,6 U
Voltage
3.1.3
internal and external insulation
air external to the components and insulating materials of the valve, but contained within the
profile of the valve or multiple valve unit is considered as part of the internal insulation system
of the valve
Note 1 to entry: The external insulation is the air between the external surface of the valve or multiple valve unit and
its surroundings.
3.1.4
valve protective firing
means of protecting the thyristors from excessive voltage by firing them at a predetermined
voltage
3.2 Valve construction terms
3.2.1
valve support
that part of the valve which mechanically supports and electrically insulates from earth the
active part of the valve which houses the valve sections
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.
3.2.2
valve structure
physical structure holding the thyristor levels of a valve which is insulated to the appropriate
voltage above earth potential
3.2.3
redundant thyristor levels
thyristor levels in the series string which may be shortcircuited, while the specified type test
performance of the valve is still met
maximum number of thyristor levels in a thyristor valve that may be short-circuited externally or
internally during service without affecting the safe operation of the thyristor valve as
demonstrated by type tests, and which if and when exceeded, would require shutdown of the
converter to replace the failed thyristors or acceptance of increased risk of failures
3.2.4
valve base electronics
electronic unit, at earth potential, which is the interface between the control system for the
converter and the thyristor valves
3.2.5
thyristor level
part of a thyristor valve comprising a thyristor, or thyristors connected in parallel, together with
their immediate auxiliaries, and reactor, if any
3.2.6
valve section
electrical assembly, comprising a number of thyristors and other components, which exhibits
pro-rated electrical properties of a complete valve
3.2.7
multiple valve unit
MVU
single physical structure comprising more than one valve with a common mechanical support
structure
– 10 – IEC 60700-1:2015 RLV © IEC 2015
3.3 Terms related to type tests
NOTE Those tests which are carried out to verify that the valve design will meet the requirements specified. In this
standard, type tests are classified under two major categories: dielectric tests and operational tests.
3.3.1
dielectric tests
tests which are carried out to verify the high voltage characteristics of the valve
3.3.2
operational tests
tests which are carried out to verify the turn-on, turn-off and current related characteristics of
the valve
3.4 Terms related to production tests
NOTE Those tests which are carried out to verify proper manufacture, so that the properties of a valve correspond
to those specified.
3.4.1
routine tests
production tests which are carried out on all valves, valve sections or components
3.4.2
sample tests
production tests which are carried out on a small number of valves, valve sections or
components taken at random from a batch
4 General requirements
4.1 Guidelines for the performance of type tests
4.1.1 Evidence in lieu
Each design of valve shall be subjected to the type tests specified in this standard. If the valve
is demonstrably similar to one previously tested, the supplier may, in lieu of performing a type
test, submit a test report of a previous type test for consideration by the purchaser. This should
be accompanied by a separate report detailing the differences in the design and demonstrating
how the referenced type test satisfies the test objectives for the proposed design.
4.1.2 Test object
Test object should meet the following requirements:
a) Certain type tests may be performed either on a complete valve or on valve sections, as
indicated in Table 2. For those type tests on valve sections, the total number of valve
sections tested shall be at least as many as the number in a complete valve.
b) The same valve sections shall be used for all type tests unless otherwise stated.
c) Prior to commencement of type tests, the valve, valve sections and/or the components of
them should be demonstrated to have withstood the production tests to ensure proper
manufacture.
4.1.3 Sequence of tests
The type tests specified can be carried out in any order.
NOTE Tests involving partial discharge measurement may can provide added confidence if performed at the end
of the dielectric type test programme.
4.1.4 Test procedures
The tests shall be performed in accordance with IEC 60060, where applicable. The
competence of testing and calibration laboratories should correspond to the
ISO/IEC Guide 17025.
4.1.5 Ambient temperature for testing
The tests shall be performed at the prevailing ambient temperature of the test facility, unless
otherwise specified.
4.1.6 Frequency for testing
AC dielectric tests can be performed at either 50 Hz or 60 Hz. For operational tests, specific
requirements regarding the frequency for testing are given in the relevant clauses.
4.1.7 Test reports
At the completion of the type tests, the supplier shall provide type test reports in accordance
with Clause 16.
4.2 Atmospheric correction
When specified in the relevant clause, atmospheric correction shall be applied to the test
voltages in accordance with IEC 60060-1. The reference conditions to which correction shall be
made are the following.
– Pressure: standard atmospheric air pressure (101,3 kPa), corrected to the altitude of the
site at which the equipment will be installed;
a) If the insulation coordination of the tested part of the thyristor valve is based on
standard rated withstand voltages according to IEC 60071-1, correction factors are only
applied for altitudes exceeding 1 000 m. Hence, if the altitude of the site a at which the
s
equipment will be installed is ≤1 000 m, then the standard atmospheric air pressure
(b = 101,3 kPa) shall be used with no correction for altitude. If a >1 000 m, then the
0 s
standard procedure according to IEC 60060-1 is used except that the reference
atmospheric pressure b is replaced by the atmospheric pressure corresponding to an
altitude of 1 000 m (b );
1 000 m
b) If the insulation coordination of the tested part of the thyristor valve is not based on
standard rated withstand voltages according to IEC 60071-1, then the standard
procedure according to IEC 60060-1 is used with the reference atmospheric pressure b
(b =101,3 kPa);
– Temperature: design maximum valve hall air temperature (°C).;
– Humidity: design minimum valve hall absolute humidity (g/m ).
The values to be used shall be specified by the supplier.
4.3 Treatment of redundancy
4.3.1 Dielectric tests
For all dielectric tests between valve terminals, the redundant thyristor levels shall be short
circuited, with the possible exception of the valve non-periodic firing test (see 8.4). The location
of thyristor levels to be short circuited shall be agreed by the purchaser and supplier.
NOTE Depending on the design, limitations may can be imposed upon the distribution of short-circuited thyristor
levels. For example, there may be an upper limit to the number of short-circuited thyristor levels in one valve
section.
– 12 – IEC 60700-1:2015 RLV © IEC 2015
4.3.2 Operational tests
For operational tests, redundant thyristor levels shall not be short circuited. The test voltages
used shall be adjusted by means of a scaling factor k :
n
N
tut
k =
n
N − N
t r
where
N is the number of series thyristor levels in the test object;
tut
is the total number of series thyristor levels in the valve;
N
t
N is the total number of redundant series thyristor levels in the valve.
r
4.4 Criteria for successful type testing
4.4.1 General
Experience in industry shows that, even with the most careful design of valves, it is not
possible to avoid occasional random failures of thyristor level components during service
operation. Even though these failures may be stress-related, they are considered random to
the extent that the cause of failure or the relationship between failure rate and stress cannot be
predicted or is not amenable to precise quantitative definition. Type tests subject valves or
valve sections, within a short time, to multiple stresses that generally correspond to the worst
stresses that can be experienced by the equipment not more than a few times during the life of
the valve. Considering the above, the criteria for successful type testing set out below therefore
permit a small number of thyristor levels to fail during type testing, providing that the failures
are rare and do not show any pattern that is indicative of inadequate design.
4.4.2 Criteria applicable to thyristor levels
The following criteria are applicable to thyristor levels:
a) If, following a type test as listed in Clause 5, more than one thyristor level (alternatively
more than 1 % of the series-connected thyristor levels in a complete valve, if greater) has
become short circuited, then the valve shall be deemed to have failed the type tests.
b) If, following a type test, one thyristor level (or more if still within the 1 % limit) has become
short circuited, then the failed level(s) shall be restored and this type test continued
repeated.
c) If the cumulative number of short-circuited thyristor levels during all type tests is more than
3 % of the series-connected thyristor levels in a complete valve, then the valve shall be
deemed to have failed the type test programme.
d) When type tests are performed on valve sections, the criteria for acceptance above also
apply since the number of valve sections tested shall be not less than the number of
sections in a complete valve (see 4.1.2 a)).
e) The valve or valve sections shall be checked after each type test to determine whether or
not any thyristor levels have become short-circuited. Failed thyristors or auxiliary
components found during or at the end of a type test may be replaced before further testing.
f) At the completion of the test programme, the valve or valve sections shall undergo a series
of check tests, which shall include as a minimum:
– check for voltage withstand of thyristor levels in both forward and reverse direction;
– check of the gating circuits where applicable;
– check of the monitoring circuits;
– check of the thyristor level protection circuits by application of transient voltages above
and below the protection setting(s) where applicable;
– check of the voltage grading circuits.
g) Thyristor level short circuits occurring during the check tests shall be counted as part of the
criteria for acceptance defined above. In addition to short-circuited levels, the total number
of thyristor levels exhibiting faults which do not result in thyristor level short circuit, which
are discovered during the type test programme and the subsequent check tests, shall not
exceed 3 % of the series-connected thyristor levels in a complete valve. If the total number
of such levels exceeds 3 %, then the nature of the faults and their cause shall be reviewed
and additional action, if any, agreed between purchaser and supplier.
h) When applying the percentage criteria to determine the permitted maximum number of
short-circuited thyristor levels and the permitted maximum number of levels with faults
which have not resulted in a thyristor level becoming short-circuited, it is usual practice to
round off all fractions to the next highest integer, as illustrated in Table 1.
Table 1 – Thyristor level faults permitted during type tests
Number of thyristor levels Number of thyristor levels Total number of thyristor Additional number of
in a complete valve minus permitted to become levels permitted to thyristor levels, in all type
the number of redundant short-circuited in any one circuited in tests, which have
become short-
levels type test all type tests experienced a fault but
(N – N ) have not become short-
t r
circuited
Up to 33 1 1 1
34 to 67 1 2 2
68 to 100 1 3 3
101 to 133 2 4 4
etc.
The distribution of short-circuited levels and of other thyristor level faults at the end of all type
tests shall be essentially random and not show any pattern that may be indicative of inadequate
design.
4.4.3 Criteria applicable to the valve as a whole
Breakdown of or external flashover across common electrical equipment associated with more
than one thyristor level of the valve, or disruptive discharge in dielectric material forming part of
the valve structure, cooling ducts, light guides or other insulating parts of the pulse
transmission and distribution system shall not be permitted.
Component and conductor surface temperatures, together with associated current-carrying
joints and connections, and the temperature of adjacent mounting surfaces shall at all times
remain within limits permitted by the design.
5 List of type tests
Table 2 below lists the type tests given in Clauses 6 to 13.
– 14 – IEC 60700-1:2015 RLV © IEC 2015
Table 2 – List of type tests
Type test Clause or subclause Test object
Valve support d.c. voltage test 6.3.2 Valve support
Valve support a.c. voltage test 6.3.3 Valve support
Valve support switching impulse test 6.3.4 Valve support
Valve support lightning impulse test 6.3.5 Valve support
MVU d.c. voltage test to earth 7.3.1 MVU
MVU a.c. voltage test 7.3.2 MVU
MVU switching impulse test 7.3.3 MVU
MVU lightning impulse test 7.3.4 MVU
Valve d.c. voltage test 8.3.1 Valve
Valve a.c. voltage test 8.3.2 Valve
Valve switching impulse test 8.3.4 Valve
Valve lightning impulse test 8.3.5 Valve
Valve steep front impulse test 8.3.6 Valve
Valve non-periodic firing test 8.4 Valve
Maximum continuous operating duty tests 9.3.2 Valve or valve-section
9.3.3 Valve or valve-section
Maximum temporary operating duty test (a = 90°)
Minimum a.c. voltage tests 9.3.4 Valve or valve-section
Temporary undervoltage test 9.3.5 Valve or valve-section
Intermittent direct current tests 9.3.6 Valve or valve-section
Tests with transient forward voltage during the recovery period 10 Valve or valve-section
One-loop fault current test with re-applied forward voltage 11.3.2 Valve or valve-section
Multiple-loop fault current test without re-applied forward voltage 11.3.3 Valve or valve-section
Tests for valve insensitivity to electromagnetic disturbance 12 Valve or valve-section
Testing of special features and fault tolerance 13 Valve or valve-section
6 Dielectric tests on valve support
6.1 Purpose of tests
The principal objectives of these tests are:
a) to verify the voltage withstand capability of the insulation of the valve support, cooling ducts,
light guides and other insulating components associated with the valve support. If there is
insulation to earth other than the valve support then additional tests may be necessary.
b) to verify that the partial discharge inception and extinction voltages are above the maximum
operating voltage appearing on the valve support.
NOTE Depending upon the application, it may can be possible to eliminate some of the tests on the valve sup
...
IEC 60700-1 ®
Edition 2.0 2015-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
Valves à thyristors pour le transport d'énergie en courant continu à haute
tension (CCHT) –
Partie 1: Essais électriques
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IEC 60700-1 ®
Edition 2.0 2015-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
Valves à thyristors pour le transport d'énergie en courant continu à haute
tension (CCHT) –
Partie 1: Essais électriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.200 ISBN 978-2-8322--2805-0
– 2 – IEC 60700-1:2015 © IEC 2015
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions. 7
3.1 Insulation co-ordination terms . 8
3.2 Valve construction terms . 9
3.3 Terms related to type tests . 10
3.4 Terms related to production tests . 10
4 General requirements . 10
4.1 Guidelines for the performance of type tests . 10
4.1.1 Evidence in lieu . 10
4.1.2 Test object . 10
4.1.3 Sequence of tests . 10
4.1.4 Test procedures . 11
4.1.5 Ambient temperature for testing . 11
4.1.6 Frequency for testing . 11
4.1.7 Test reports . 11
4.2 Atmospheric correction . 11
4.3 Treatment of redundancy . 11
4.3.1 Dielectric tests . 11
4.3.2 Operational tests . 11
4.4 Criteria for successful type testing . 12
4.4.1 General . 12
4.4.2 Criteria applicable to thyristor levels . 12
4.4.3 Criteria applicable to the valve as a whole . 13
5 List of type tests . 13
6 Dielectric tests on valve support . 14
6.1 Purpose of tests . 14
6.2 Test object . 14
6.3 Test requirements . 15
6.3.1 General . 15
6.3.2 Valve support d.c. voltage test . 15
6.3.3 Valve support a.c. voltage test . 15
6.3.4 Valve support switching impulse test . 16
6.3.5 Valve support lightning impulse test . 16
7 Dielectric tests for multiple valve units (MVU) . 16
7.1 Purpose of tests . 16
7.2 Test object . 16
7.3 Test requirements . 17
7.3.1 MVU d.c. voltage test to earth . 17
7.3.2 MVU a.c. voltage test . 18
7.3.3 MVU switching impulse test . 18
7.3.4 MVU lightning impulse test . 19
8 Dielectric tests between valve terminals . 20
8.1 Purpose of tests . 20
8.2 Test object . 20
8.3 Test requirements . 20
8.3.1 Valve d.c. voltage test . 20
8.3.2 Valve a.c. voltage test . 21
8.3.3 Valve impulse tests (general) . 22
8.3.4 Valve switching impulse test . 23
8.3.5 Valve lightning impulse test . 23
8.3.6 Valve steep front impulse test . 23
8.4 Valve non-periodic firing test . 24
8.4.1 Purpose of test . 24
8.4.2 Test object . 24
8.4.3 Test requirements . 24
9 Periodic firing and extinction tests . 25
9.1 Purpose of tests . 25
9.2 Test object . 26
9.3 Test requirements . 26
9.3.1 General . 26
9.3.2 Maximum continuous operating duty tests . 27
9.3.3 Maximum temporary operating duty test (α = 90°) . 28
9.3.4 Minimum a.c. voltage tests . 29
9.3.5 Temporary undervoltage test . 30
9.3.6 Intermittent direct current tests . 31
10 Tests with transient forward voltage during the recovery period . 31
10.1 Purpose of tests . 31
10.2 Test object . 31
10.3 Test requirements . 31
11 Valve fault current tests . 33
11.1 Purpose of tests . 33
11.2 Test object . 33
11.3 Test requirements . 33
11.3.1 General . 33
11.3.2 One-loop fault current test with re-applied forward voltage . 34
11.3.3 Multiple-loop fault current test without re-applied forward voltage . 35
12 Tests for valve insensitivity to electromagnetic disturbance . 35
12.1 Purpose of tests . 35
12.2 Test object . 36
12.3 Test requirements . 36
12.3.1 General . 36
12.3.2 Approach one . 36
12.3.3 Approach two . 36
12.3.4 Acceptance criteria . 37
13 Testing of special features and fault tolerance . 37
13.1 Purpose of tests . 37
13.1.1 General . 37
13.1.2 Circuits to facilitate the proper control, protection and monitoring of the
valve . 37
13.1.3 Features included in the valve to provide fault tolerance . 37
13.2 Test object . 37
13.3 Test requirements . 38
14 Production tests . 38
– 4 – IEC 60700-1:2015 © IEC 2015
14.1 General . 38
14.2 Purpose of tests . 38
14.3 Test object . 38
14.4 Test requirements . 38
14.5 Routine test – minimum requirements . 38
14.5.1 Visual inspection . 38
14.5.2 Connection check . 39
14.5.3 Voltage-grading circuit check . 39
14.5.4 Voltage withstand check . 39
14.5.5 Partial discharge tests . 39
14.5.6 Check of auxiliaries . 39
14.5.7 Firing check . 39
14.5.8 Pressure test . 39
15 Method for loss determination . 39
16 Presentation of type test results . 39
Annex A (normative) Test safety factors . 40
A.1 General . 40
A.2 Test safety factors for dielectric tests . 40
A.2.1 Impulse tests . 40
A.2.2 AC and d.c. temporary and long-term voltage tests . 43
A.3 Test safety factors for operational tests . 43
Annex B (normative) Partial discharge measurements . 44
B.1 Measurement of partial discharge . 44
B.2 Partial discharge during a.c. tests . 44
B.3 Partial discharge during d.c. tests . 44
B.4 Composite a.c. plus d.c. voltage stress . 45
Figure 1 – Steep front impulse test voltage . 8
Table 1 – Thyristor level faults permitted during type tests . 13
Table 2 – List of type tests . 14
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THYRISTOR VALVES FOR HIGH VOLTAGE DIRECT
CURRENT (HVDC) POWER TRANSMISSION –
Part 1: Electrical testing
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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 60700-1 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 second edition cancels and replaces the first edition published in 1998, its Amendment
1:2003 and its Amendment 2: 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition.
a) Definitions of terms “redundant thyristor levels”, “thyristor level”, “valve section” have been
changed for clarification.
b) The notes were added to test requirements of dielectric d.c. voltage tests for valve support,
MVU, valve, specifying that before repeating the test with opposite polarity, the tested
– 6 – IEC 60700-1:2015 © IEC 2015
object may be short-circuited and earthed for several hours. The same procedure may be
followed at the end of the d.c. voltage test.
c) Table 1 on thyristor level faults permitted during type tests was supplemented.
d) The alternative MVU dielectric test method was added.
e) It was specified that production tests may include routine tests as well as sample tests.
f) It was added into test requirements for periodic firing and extinction tests that a scaling
factor for tests shall be applied when testing with valve sections.
The text of this standard is based on the following documents:
CDV Report on voting
22F/341/CDV 22F/351A/RVC
Full information on the voting for the approval of this 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.
A list of all parts in the IEC 60700 series, published under the general title Thyristor valves for
high voltage direct current (HVDC) power transmission, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC website 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.
The contents of the corrigendum of January 2017 have been included in this copy.
THYRISTOR VALVES FOR HIGH VOLTAGE DIRECT
CURRENT (HVDC) POWER TRANSMISSION –
Part 1: Electrical testing
1 Scope
This part of IEC 60700 applies to thyristor valves with metal oxide surge arresters directly
connected between the valve terminals, for use in a line commutated converter for high voltage
d.c. power transmission or as part of a back-to-back link. It is restricted to electrical type and
production tests.
The tests specified in this standard are based on air insulated valves. For other types of valves,
the test requirements and acceptance criteria can be agreed.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
IEC 60060, High-voltage test techniques
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60099 (all parts), Surge arresters
IEC 60270, High-voltage test techniques – Partial discharge measurements
IEC 61803:1999, Determination of power losses in high-voltage direct current (HVDC)
converter stations
IEC 61803:1999/AMD 1:2010
ISO/IEC Guide 25, General requirements for the technical competence of testing laboratories
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
___________
There exists a consolidated edition 1.1 (2011) that comprises IEC 61803:1999 and its Amendment 1:2010.
Withdrawn.
– 8 – IEC 60700-1:2015 © IEC 2015
3.1 Insulation co-ordination terms
3.1.1
test withstand voltage
value of a test voltage of standard waveshape at which a new valve, with unimpaired integrity,
does not show any disruptive discharge and meets all other acceptance criteria specified for
the particular test, when subjected to a specified number of applications or a specified duration
of the test voltage, under specified conditions
3.1.2
steep front impulse
fast-front voltage impulse whose time to peak is less than that of a standard lightning impulse
but not less than that of a very-fast-front voltage as defined in IEC 60071-1
Note 1 to entry: For this standard, the steep front impulse voltage for test purposes is as shown in Figure 1.
Steepness S
Peak value U
0,2 T
0,5 U
T
Time
T
IEC
Key
U specified peak value of steep front impulse test voltage (kV)
S specified steepness of steep front impulse test voltage (kV/µs)
U
T virtual front time = (µs)
S
The following conditions shall be satisfied:
a) The peak value of the recorded test voltage shall be U ± 3 %. This tolerance is the same as that in IEC 60060
for standard lightning impulse.
b) Over a voltage excursion of not less than 0,6 U, the rising portion of the recorded test voltage shall be entirely
contained between two parallel lines of steepness S and separation 0,2 T
1.
c) The value of the test voltage at T shall not be lower than 0,5 U. T is defined as the time interval between the
2 2
origin and the instant when the voltage has decreased to half the peak value of the waveform which is obtained
from system study. However, it shall be assured that an unintentional du/dt switching of the thyristors can be
adequately detected.
Figure 1 – Steep front impulse test voltage
0,6 U
Voltage
3.1.3
internal and external insulation
air external to the components and insulating materials of the valve, but contained within the
profile of the valve or multiple valve unit is considered as part of the internal insulation system
of the valve
Note 1 to entry: The external insulation is the air between the external surface of the valve or multiple valve unit and
its surroundings.
3.1.4
valve protective firing
means of protecting the thyristors from excessive voltage by firing them at a predetermined
voltage
3.2 Valve construction terms
3.2.1
valve support
that part of the valve which mechanically supports and electrically insulates from earth the
active part of the valve which houses the valve sections
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.
3.2.2
valve structure
physical structure holding the thyristor levels of a valve which is insulated to the appropriate
voltage above earth potential
3.2.3
redundant thyristor levels
maximum number of thyristor levels in a thyristor valve that may be short-circuited externally or
internally during service without affecting the safe operation of the thyristor valve as
demonstrated by type tests, and which if and when exceeded, would require shutdown of the
converter to replace the failed thyristors or acceptance of increased risk of failures
3.2.4
valve base electronics
electronic unit, at earth potential, which is the interface between the control system for the
converter and the thyristor valves
3.2.5
thyristor level
part of a thyristor valve comprising a thyristor, or thyristors connected in parallel, together with
their immediate auxiliaries, and reactor, if any
3.2.6
valve section
electrical assembly, comprising a number of thyristors and other components, which exhibits
pro-rated electrical properties of a complete valve
3.2.7
multiple valve unit
MVU
single physical structure comprising more than one valve with a common mechanical support
structure
– 10 – IEC 60700-1:2015 © IEC 2015
3.3 Terms related to type tests
NOTE Those tests which are carried out to verify that the valve design will meet the requirements specified. In this
standard, type tests are classified under two major categories: dielectric tests and operational tests.
3.3.1
dielectric tests
tests which are carried out to verify the high voltage characteristics of the valve
3.3.2
operational tests
tests which are carried out to verify the turn-on, turn-off and current related characteristics of
the valve
3.4 Terms related to production tests
NOTE Those tests which are carried out to verify proper manufacture, so that the properties of a valve correspond
to those specified.
3.4.1
routine tests
production tests which are carried out on all valves, valve sections or components
3.4.2
sample tests
production tests which are carried out on a small number of valves, valve sections or
components taken at random from a batch
4 General requirements
4.1 Guidelines for the performance of type tests
4.1.1 Evidence in lieu
Each design of valve shall be subjected to the type tests specified in this standard. If the valve
is demonstrably similar to one previously tested, the supplier may, in lieu of performing a type
test, submit a test report of a previous type test for consideration by the purchaser. This should
be accompanied by a separate report detailing the differences in the design and demonstrating
how the referenced type test satisfies the test objectives for the proposed design.
4.1.2 Test object
Test object should meet the following requirements:
a) Certain type tests may be performed either on a complete valve or on valve sections, as
indicated in Table 2. For those type tests on valve sections, the total number of valve
sections tested shall be at least as many as the number in a complete valve.
b) The same valve sections shall be used for all type tests unless otherwise stated.
c) Prior to commencement of type tests, the valve, valve sections and/or the components of
them should be demonstrated to have withstood the production tests to ensure proper
manufacture.
4.1.3 Sequence of tests
The type tests specified can be carried out in any order.
NOTE Tests involving partial discharge measurement can provide added confidence if performed at the end of the
dielectric type test programme.
4.1.4 Test procedures
The tests shall be performed in accordance with IEC 60060, where applicable. The
competence of testing and calibration laboratories should correspond to the
ISO/IEC Guide 17025.
4.1.5 Ambient temperature for testing
The tests shall be performed at the prevailing ambient temperature of the test facility, unless
otherwise specified.
4.1.6 Frequency for testing
AC dielectric tests can be performed at either 50 Hz or 60 Hz. For operational tests, specific
requirements regarding the frequency for testing are given in the relevant clauses.
4.1.7 Test reports
At the completion of the type tests, the supplier shall provide type test reports in accordance
with Clause 16.
4.2 Atmospheric correction
When specified in the relevant clause, atmospheric correction shall be applied to the test
voltages in accordance with IEC 60060-1. The reference conditions to which correction shall be
made are the following.
– Pressure:
a) If the insulation coordination of the tested part of the thyristor valve is based on
standard rated withstand voltages according to IEC 60071-1, correction factors are only
applied for altitudes exceeding 1 000 m. Hence, if the altitude of the site a at which the
s
equipment will be installed is ≤1 000 m, then the standard atmospheric air pressure
(b = 101,3 kPa) shall be used with no correction for altitude. If a >1 000 m, then the
0 s
standard procedure according to IEC 60060-1 is used except that the reference
atmospheric pressure b is replaced by the atmospheric pressure corresponding to an
altitude of 1 000 m (b );
1 000 m
b) If the insulation coordination of the tested part of the thyristor valve is not based on
standard rated withstand voltages according to IEC 60071-1, then the standard
procedure according to IEC 60060-1 is used with the reference atmospheric pressure b
(b =101,3 kPa);
– Temperature: design maximum valve hall air temperature (°C).;
– Humidity: design minimum valve hall absolute humidity (g/m ).
The values to be used shall be specified by the supplier.
4.3 Treatment of redundancy
4.3.1 Dielectric tests
For all dielectric tests between valve terminals, the redundant thyristor levels shall be short
circuited, with the possible exception of the valve non-periodic firing test (see 8.4). The location
of thyristor levels to be short circuited shall be agreed by the purchaser and supplier.
NOTE Depending on the design, limitations can be imposed upon the distribution of short-circuited thyristor levels.
For example, there may be an upper limit to the number of short-circuited thyristor levels in one valve section.
4.3.2 Operational tests
For operational tests, redundant thyristor levels shall not be short circuited. The test voltages
used shall be adjusted by means of a scaling factor k :
n
– 12 – IEC 60700-1:2015 © IEC 2015
N
tut
k =
n
N − N
t r
where
N is the number of series thyristor levels in the test object;
tut
N is the total number of series thyristor levels in the valve;
t
N is the total number of redundant series thyristor levels in the valve.
r
4.4 Criteria for successful type testing
4.4.1 General
Experience in industry shows that, even with the most careful design of valves, it is not
possible to avoid occasional random failures of thyristor level components during service
operation. Even though these failures may be stress-related, they are considered random to
the extent that the cause of failure or the relationship between failure rate and stress cannot be
predicted or is not amenable to precise quantitative definition. Type tests subject valves or
valve sections, within a short time, to multiple stresses that generally correspond to the worst
stresses that can be experienced by the equipment not more than a few times during the life of
the valve. Considering the above, the criteria for successful type testing set out below therefore
permit a small number of thyristor levels to fail during type testing, providing that the failures
are rare and do not show any pattern that is indicative of inadequate design.
4.4.2 Criteria applicable to thyristor levels
The following criteria are applicable to thyristor levels:
a) If, following a type test as listed in Clause 5, more than one thyristor level (alternatively
more than 1 % of the series-connected thyristor levels in a complete valve, if greater) has
become short circuited, then the valve shall be deemed to have failed the type tests.
b) If, following a type test, one thyristor level (or more if still within the 1 % limit) has become
short circuited, then the failed level(s) shall be restored and this type test repeated.
c) If the cumulative number of short-circuited thyristor levels during all type tests is more than
3 % of the series-connected thyristor levels in a complete valve, then the valve shall be
deemed to have failed the type test programme.
d) When type tests are performed on valve sections, the criteria for acceptance above also
apply since the number of valve sections tested shall be not less than the number of
sections in a complete valve (see 4.1.2 a)).
e) The valve or valve sections shall be checked after each type test to determine whether or
not any thyristor levels have become short-circuited. Failed thyristors or auxiliary
components found during or at the end of a type test may be replaced before further testing.
f) At the completion of the test programme, the valve or valve sections shall undergo a series
of check tests, which shall include as a minimum:
– check for voltage withstand of thyristor levels in both forward and reverse direction;
– check of the gating circuits where applicable;
– check of the monitoring circuits;
– check of the thyristor level protection circuits by application of transient voltages above
and below the protection setting(s) where applicable;
– check of the voltage grading circuits.
g) Thyristor level short circuits occurring during the check tests shall be counted as part of the
criteria for acceptance defined above. In addition to short-circuited levels, the total number
of thyristor levels exhibiting faults which do not result in thyristor level short circuit, which
are discovered during the type test programme and the subsequent check tests, shall not
exceed 3 % of the series-connected thyristor levels in a complete valve. If the total number
of such levels exceeds 3 %, then the nature of the faults and their cause shall be reviewed
and additional action, if any, agreed between purchaser and supplier.
h) When applying the percentage criteria to determine the permitted maximum number of
short-circuited thyristor levels and the permitted maximum number of levels with faults
which have not resulted in a thyristor level becoming short-circuited, it is usual practice to
round off all fractions to the next highest integer, as illustrated in Table 1.
Table 1 – Thyristor level faults permitted during type tests
Number of thyristor levels Number of thyristor levels Total number of thyristor Additional number of
in a complete valve minus permitted to become levels permitted to thyristor levels, in all type
the number of redundant short-circuited in any one circuited in tests, which have
become short-
levels type test all type tests experienced a fault but
(N – N ) have not become short-
t r
circuited
Up to 33 1 1 1
34 to 67 1 2 2
68 to 100 1 3 3
101 to 133 2 4 4
etc.
The distribution of short-circuited levels and of other thyristor level faults at the end of all type
tests shall be essentially random and not show any pattern that may be indicative of inadequate
design.
4.4.3 Criteria applicable to the valve as a whole
Breakdown of or external flashover across common electrical equipment associated with more
than one thyristor level of the valve, or disruptive discharge in dielectric material forming part of
the valve structure, cooling ducts, light guides or other insulating parts of the pulse
transmission and distribution system shall not be permitted.
Component and conductor surface temperatures, together with associated current-carrying
joints and connections, and the temperature of adjacent mounting surfaces shall at all times
remain within limits permitted by the design.
5 List of type tests
Table 2 below lists the type tests given in Clauses 6 to 13.
– 14 – IEC 60700-1:2015 © IEC 2015
Table 2 – List
...
IEC 60700-1 ®
Edition 2.1 2021-09
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
Valves à thyristors pour le transport d'énergie en courant continu à haute
tension (CCHT) –
Partie 1: Essais électriques
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IEC 60700-1 ®
Edition 2.1 2021-09
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
Valves à thyristors pour le transport d'énergie en courant continu à haute
tension (CCHT) –
Partie 1: Essais électriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.200 ISBN 978-2-8322-4450-0
IEC 60700-1 ®
Edition 2.1 2021-09
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Thyristor valves for high voltage direct current (HVDC) power transmission –
Part 1: Electrical testing
Valves à thyristors pour le transport d'énergie en courant continu à haute
tension (CCHT) –
Partie 1: Essais électriques
– 2 – IEC 60700-1:2015+AMD1:2021 CSV
© IEC 2021
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references. 7
3 Terms and definitions . 7
3.1 Insulation co-ordination terms . 8
3.2 Valve construction terms .
3.3 Terms related to type tests . 9
3.4 Terms related to production tests. 10
4 General requirements . 10
4.1 Guidelines for the performance of type tests . 10
4.1.1 Evidence in lieu . 10
4.1.2 Test object . 10
4.1.3 Sequence of tests . 10
4.1.4 Test procedures . 10
4.1.5 Ambient temperature for testing . 11
4.1.6 Frequency for testing . 11
4.1.7 Test reports . 11
4.2 Atmospheric correction . 11
4.3 Treatment of redundancy . 11
4.3.1 Dielectric tests . 11
4.3.2 Operational tests . 11
4.4 Criteria for successful type testing . 12
4.4.1 General . 12
4.4.2 Criteria applicable to thyristor levels . 12
4.4.3 Criteria applicable to the valve as a whole . 13
5 List of type tests . 13
6 Dielectric tests on valve support . 14
6.1 Purpose of tests . 14
6.2 Test object . 14
6.3 Test requirements . 15
6.3.1 General . 15
6.3.2 Valve support d.c. voltage test . 15
6.3.3 Valve support a.c. voltage test . 15
6.3.4 Valve support switching impulse test . 16
6.3.5 Valve support lightning impulse test . 16
7 Dielectric tests for multiple valve units (MVU) . 16
7.1 Purpose of tests . 16
7.2 Test object . 16
7.3 Test requirements . 17
7.3.1 MVU d.c. voltage test to earth . 17
7.3.2 MVU a.c. voltage test . 18
7.3.3 MVU switching impulse test . 18
7.3.4 MVU lightning impulse test . 19
8 Dielectric tests between valve terminals . 20
8.1 Purpose of tests . 20
© IEC 2021
8.2 Test object . 20
8.3 Test requirements . 21
8.3.1 Valve d.c. voltage test . 21
8.3.2 Valve a.c. voltage test . 21
8.3.3 Valve impulse tests (general) . 22
8.3.4 Valve switching impulse test . 23
8.3.5 Valve lightning impulse test . 23
8.3.6 Valve steep front impulse test . 24
8.4 Valve non-periodic firing test . 24
8.4.1 Purpose of test . 24
8.4.2 Test object . 24
8.4.3 Test requirements . 25
9 Periodic firing and extinction tests . 26
9.1 Purpose of tests . 26
9.2 Test object . 26
9.3 Test requirements . 26
9.3.1 General . 26
9.3.2 Maximum continuous operating duty tests . 27
9.3.3 Maximum temporary operating duty test (α = 90°) . 29
9.3.4 Minimum a.c. voltage tests . 29
9.3.5 Temporary undervoltage test . 30
9.3.6 Intermittent direct current tests . 31
10 Tests with transient forward voltage during the recovery period . 32
10.1 Purpose of tests . 32
10.2 Test object . 32
10.3 Test requirements . 32
11 Valve fault current tests . 33
11.1 Purpose of tests . 33
11.2 Test object . 33
11.3 Test requirements . 33
11.3.1 General . 33
11.3.2 One-loop fault current test with re-applied forward voltage . 34
11.3.3 Multiple-loop fault current test without re-applied forward voltage . 35
12 Tests for valve insensitivity to electromagnetic disturbance . 36
12.1 Purpose of tests . 36
12.2 Test object . 36
12.3 Test requirements . 36
12.3.1 General . 36
12.3.2 Approach one . 36
12.3.3 Approach two . 37
12.3.4 Acceptance criteria . 37
13 Testing of special features and fault tolerance . 37
13.1 Purpose of tests . 37
13.1.1 General . 37
13.1.2 Circuits to facilitate the proper control, protection and monitoring of the
valve . 37
13.1.3 Features included in the valve to provide fault tolerance . 37
13.2 Test object . 38
– 4 – IEC 60700-1:2015+AMD1:2021 CSV
© IEC 2021
13.3 Test requirements . 38
14 Production tests . 38
14.1 General . 38
14.2 Purpose of tests . 38
14.3 Test object . 39
14.4 Test requirements . 39
14.5 Routine test – minimum requirements . 39
14.5.1 Visual inspection . 39
14.5.2 Connection check . 39
14.5.3 Voltage-grading circuit check . 39
14.5.4 Voltage withstand check . 39
14.5.5 Partial discharge tests . 39
14.5.6 Check of auxiliaries . 39
14.5.7 Firing check . 39
14.5.8 Pressure test . 39
15 Method for loss determination . 40
16 Presentation of type test results . 40
Annex A (normative) Test safety factors . 41
A.1 General . 41
A.2 Test safety factors for dielectric tests . 41
A.2.1 Impulse tests . 41
A.2.2 AC and d.c. temporary and long-term voltage tests . 44
A.3 Test safety factors for operational tests . 44
Annex B (normative) Partial discharge measurements . 45
B.1 Measurement of partial discharge . 45
B.2 Partial discharge during a.c. tests . 45
B.3 Partial discharge during d.c. tests . 45
B.4 Composite a.c. plus d.c. voltage stress . 46
Bibliography . 47
Figure 1 – Steep front impulse test voltage . 8
Table 1 – Thyristor level faults permitted during type tests . 13
Table 2 – List of type tests . 14
© IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THYRISTOR VALVES FOR HIGH VOLTAGE DIRECT
CURRENT (HVDC) POWER TRANSMISSION –
Part 1: Electrical testing
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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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.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60700-1 edition 2.1 contains the second edition (2015-07) [documents 22F/341/CDV
and 22F/351A/RVC], its corrigendum 1 (2017-01) and its amendment 1 (2021-09)
[documents 22F/604/CDV and 22F/628/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
– 6 – IEC 60700-1:2015+AMD1:2021 CSV
© IEC 2021
International Standard IEC 60700-1 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 second edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition.
a) Definitions of terms “redundant thyristor levels”, “thyristor level”, “valve section” have been
changed for clarification.
b) The notes were added to test requirements of dielectric d.c. voltage tests for valve support,
MVU, valve, specifying that before repeating the test with opposite polarity, the tested
object may be short-circuited and earthed for several hours. The same procedure may be
followed at the end of the d.c. voltage test.
c) Table 1 on thyristor level faults permitted during type tests was supplemented.
d) The alternative MVU dielectric test method was added.
e) It was specified that production tests may include routine tests as well as sample tests.
f) It was added into test requirements for periodic firing and extinction tests that a scaling
factor for tests shall be applied when testing with valve sections.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60700 series, published under the general title Thyristor valves for
high voltage direct current (HVDC) power transmission, can be found on the IEC website.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under 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.
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.
© IEC 2021
THYRISTOR VALVES FOR HIGH VOLTAGE DIRECT
CURRENT (HVDC) POWER TRANSMISSION –
Part 1: Electrical testing
1 Scope
This part of IEC 60700 applies to thyristor valves with metal oxide surge arresters directly
connected between the valve terminals, for use in a line commutated converter for high
voltage d.c. power transmission or as part of a back-to-back link. It is restricted to electrical
type and production tests.
The tests specified in this standard are based on air insulated valves. For other types of
valves, the test requirements and acceptance criteria can be agreed.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60060, High-voltage test techniques
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60099 (all parts), Surge arresters
IEC 60270, High-voltage test techniques – Partial discharge measurements
IEC 61803:1999, Determination of power losses in high-voltage direct current (HVDC)
converter stations
IEC 61803:1999/AMD 1:2010
IEC 61803:2020, Determination of power losses in high-voltage direct current (HVDC)
converter stations with line-commutated converters
ISO/IEC Guide 25, General requirements for the technical competence of testing laboratories
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
___________
There exists a consolidated edition 1.1 (2011) that comprises IEC 61803:1999 and its Amendment 1:2010.
Withdrawn.
– 8 – IEC 60700-1:2015+AMD1:2021 CSV
© IEC 2021
3.1 Insulation co-ordination terms
3.1.1
test withstand voltage
value of a test voltage of standard waveshape at which a new valve, with unimpaired integrity,
does not show any disruptive discharge and meets all other acceptance criteria specified for
the particular test, when subjected to a specified number of applications or a specified
duration of the test voltage, under specified conditions
3.1.2
steep front impulse
fast-front voltage impulse whose time to peak is less than that of a standard lightning impulse
but not less than that of a very-fast-front voltage as defined in IEC 60071-1
Note 1 to entry: For this standard, the steep front impulse voltage for test purposes is as shown in Figure 1.
Steepness S
Peak value U
0,2 T1
0,5 U
T1
Time
T2
IEC
Key
U specified peak value of steep front impulse test voltage (kV)
S specified steepness of steep front impulse test voltage (kV/µs)
U
T virtual front time = (µs)
S
The following conditions shall be satisfied:
a) The peak value of the recorded test voltage shall be U ± 3 %. This tolerance is the same as that in IEC 60060
for standard lightning impulse.
b) Over a voltage excursion of not less than 0,6 U, the rising portion of the recorded test voltage shall be entirely
contained between two parallel lines of steepness S and separation 0,2 T
1.
c) The value of the test voltage at T shall not be lower than 0,5 U. T is defined as the time interval between the
2 2
origin and the instant when the voltage has decreased to half the peak value of the waveform which is obtained
from system study. However, it shall be assured that an unintentional du/dt switching of the thyristors can be
adequately detected.
Figure 1 – Steep front impulse test voltage
0,6 U
Voltage
© IEC 2021
3.1.3
internal and external insulation
air external to the components and insulating materials of the valve, but contained within the
profile of the valve or multiple valve unit is considered as part of the internal insulation system
of the valve
Note 1 to entry: The external insulation is the air between the external surface of the valve or multiple valve unit
and its surroundings.
3.1.4
valve protective firing
means of protecting the thyristors from excessive voltage by firing them at a predetermined
voltage
3.2 Valve construction terms
3.2.1
valve support
that part of the valve which mechanically supports and electrically insulates from earth the
active part of the valve which houses the valve sections
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.
3.2.2
valve structure
physical structure holding the thyristor levels of a valve which is insulated to the appropriate
voltage above earth potential
3.2.3
redundant thyristor levels
maximum number of thyristor levels in a thyristor valve that may be short-circuited externally
or internally during service without affecting the safe operation of the thyristor valve as
demonstrated by type tests, and which if and when exceeded, would require shutdown of the
converter to replace the failed thyristors or acceptance of increased risk of failures
3.2.4
valve base electronics
electronic unit, at earth potential, which is the interface between the control system for the
converter and the thyristor valves
3.2.5
thyristor level
part of a thyristor valve comprising a thyristor, or thyristors connected in parallel, together
with their immediate auxiliaries, and reactor, if any
3.2.6
valve section
electrical assembly, comprising a number of thyristors and other components, which exhibits
pro-rated electrical properties of a complete valve
3.2.7
multiple valve unit
MVU
single physical structure comprising more than one valve with a common mechanical support
structure
3.3 Terms related to type tests
NOTE Those tests which are carried out to verify that the valve design will meet the requirements specified. In
this standard, type tests are classified under two major categories: dielectric tests and operational tests.
– 10 – IEC 60700-1:2015+AMD1:2021 CSV
© IEC 2021
3.3.1
dielectric tests
tests which are carried out to verify the high voltage characteristics of the valve
3.3.2
operational tests
tests which are carried out to verify the turn-on, turn-off and current related characteristics of
the valve
3.4 Terms related to production tests
NOTE Those tests which are carried out to verify proper manufacture, so that the properties of a valve correspond
to those specified.
3.4.1
routine tests
production tests which are carried out on all valves, valve sections or components
3.4.2
sample tests
production tests which are carried out on a small number of valves, valve sections or
components taken at random from a batch
4 General requirements
4.1 Guidelines for the performance of type tests
4.1.1 Evidence in lieu
Each design of valve shall be subjected to the type tests specified in this standard. If the
valve is demonstrably similar to one previously tested, the supplier may, in lieu of performing
a type test, submit a test report of a previous type test for consideration by the purchaser.
This should be accompanied by a separate report detailing the differences in the design and
demonstrating how the referenced type test satisfies the test objectives for the proposed
design.
4.1.2 Test object
Test object should meet the following requirements:
a) Certain type tests may be performed either on a complete valve or on valve sections, as
indicated in Table 2. For those type tests on valve sections, the total number of valve
sections tested shall be at least as many as the number in a complete valve.
b) The same valve sections shall be used for all type tests unless otherwise stated.
c) Prior to commencement of type tests, the valve, valve sections and/or the components of
them should be demonstrated to have withstood the production tests to ensure proper
manufacture.
4.1.3 Sequence of tests
The type tests specified can be carried out in any order.
NOTE Tests involving partial discharge measurement can provide added confidence if performed at the end of the
dielectric type test programme.
4.1.4 Test procedures
The tests shall be performed in accordance with IEC 60060, where applicable. The
competence of testing and calibration laboratories should correspond to the
ISO/IEC Guide 17025.
© IEC 2021
4.1.5 Ambient temperature for testing
The tests shall be performed at the prevailing ambient temperature of the test facility, unless
otherwise specified.
4.1.6 Frequency for testing
AC dielectric tests can be performed at either 50 Hz or 60 Hz. For operational tests, specific
requirements regarding the frequency for testing are given in the relevant clauses.
4.1.7 Test reports
At the completion of the type tests, the supplier shall provide type test reports in accordance
with Clause 16.
4.2 Atmospheric correction
When specified in the relevant clause, atmospheric correction shall be applied to the test
voltages in accordance with IEC 60060-1. The reference conditions to which correction shall
be made are the following.
– Pressure:
a) If the insulation coordination of the tested part of the thyristor valve is based on
standard rated withstand voltages according to IEC 60071-1, correction factors are
only applied for altitudes exceeding 1 000 m. Hence, if the altitude of the site a at
s
which the equipment will be installed is ≤1 000 m, then the standard atmospheric air
pressure (b = 101,3 kPa) shall be used with no correction for altitude. If a >1 000 m,
0 s
then the standard procedure according to IEC 60060-1 is used except that the
reference atmospheric pressure b is replaced by the atmospheric pressure
corresponding to an altitude of 1 000 m (b );
1 000 m
b) If the insulation coordination of the tested part of the thyristor valve is not based on
standard rated withstand voltages according to IEC 60071-1, then the standard
procedure according to IEC 60060-1 is used with the reference atmospheric pressure
b (b =101,3 kPa);
0 0
– Temperature: design maximum valve hall air temperature (°C).;
– Humidity: design minimum valve hall absolute humidity (g/m ).
The values to be used shall be specified by the supplier.
4.3 Treatment of redundancy
4.3.1 Dielectric tests
For all dielectric tests between valve terminals, the redundant thyristor levels shall be short
circuited, with the possible exception of the valve non-periodic firing test (see 8.4). The
location of thyristor levels to be short circuited shall be agreed by the purchaser and supplier.
NOTE Depending on the design, limitations can be imposed upon the distribution of short-circuited thyristor levels.
For example, there may be an upper limit to the number of short-circuited thyristor levels in one valve section.
4.3.2 Operational tests
For operational tests, redundant thyristor levels shall not be short circuited. The test voltages
used shall be adjusted by means of a scaling factor k :
n
N
tut
k =
n
N − N
t r
where
– 12 – IEC 60700-1:2015+AMD1:2021 CSV
© IEC 2021
N is the number of series thyristor levels in the test object;
tut
N is the total number of series thyristor levels in the valve;
t
N is the total number of redundant series thyristor levels in the valve.
r
4.4 Criteria for successful type testing
4.4.1 General
Experience in industry shows that, even with the most careful design of valves, it is not
possible to avoid occasional random failures of thyristor level components during service
operation. Even though these failures may be stress-related, they are considered random to
the extent that the cause of failure or the relationship between failure rate and stress cannot
be predicted or is not amenable to precise quantitative definition. Type tests subject valves or
valve sections, within a short time, to multiple stresses that generally correspond to the worst
stresses that can be experienced by the equipment not more than a few times during the life
of the valve. Considering the above, the criteria for successful type testing set out below
therefore permit a small number of thyristor levels to fail during type testing, providing that the
failures are rare and do not show any pattern that is indicative of inadequate design.
4.4.2 Criteria applicable to thyristor levels
The following criteria are applicable to thyristor levels:
a) If, following a type test as listed in Clause 5, more than one thyristor level (alternatively
more than 1 % of the series-connected thyristor levels in a complete valve, if greater) has
become short circuited, then the valve shall be deemed to have failed the type tests.
b) If, following a type test, one thyristor level (or more if still within the 1 % limit) has become
short circuited, then the failed level(s) shall be restored and this type test repeated.
c) If the cumulative number of short-circuited thyristor levels during all type tests is more
than 3 % of the series-connected thyristor levels in a complete valve, then the valve shall
be deemed to have failed the type test programme.
d) When type tests are performed on valve sections, the criteria for acceptance above also
apply since the number of valve sections tested shall be not less than the number of
sections in a complete valve (see 4.1.2 a)).
e) The valve or valve sections shall be checked after each type test to determine whether or
not any thyristor levels have become short-circuited. Failed thyristors or auxiliary
components found during or at the end of a type test may be replaced before further
testing.
f) At the completion of the test programme, the valve or valve sections shall undergo a
series of check tests, which shall include as a minimum:
– check for voltage withstand of thyristor levels in both forward and reverse direction;
– check of the gating circuits where applicable;
– check of the monitoring circuits;
– check of the thyristor level protection circuits by application of transient voltages above
and below the protection setting(s) where applicable;
– check of the voltage grading circuits.
g) Thyristor level short circuits occurring during the check tests shall be counted as part of
the criteria for acceptance defined above. In addition to short-circuited levels, the total
number of thyristor levels exhibiting faults which do not result in thyristor level short circuit,
which are discovered during the type test programme and the subsequent check tests,
shall not exceed 3 % of the series-connected thyristor levels in a complete valve. If the
total number of such levels exceeds 3 %, then the nature of the faults and their cause
shall be reviewed and additional action, if any, agreed between purchaser and supplier.
h) When applying the percentage criteria to determine the permitted maximum number of
short-circuited thyristor levels and the permitted maximum number of levels with faults
© IEC 2021
which have not resulted in a thyristor level becoming short-circuited, it is usual practice to
round off all fractions to the next highest integer, as illustrated in Table 1.
Table 1 – Thyristor level faults permitted during type tests
Number of thyristor levels Number of thyristor levels Total number of thyristor Additional number of
in a complete valve minus permitted to become levels permitted to thyristor levels, in all type
the number of redundant short-circuited in any one become short-circuited in tests, which have
levels type test all type tests experienced a fault but
(N – N ) have not become short-
t r
circuited
Up to 33 1 1 1
34 to 67 1 2 2
68 to 100 1 3 3
101 to 133 2 4 4
etc.
The distribution of short-circuited levels and of other thyristor level faults at the end of all type
tests shall be essentially random and not show any pattern that may be indicative of
inadequate design.
4.4.3 Criteria applicable to the valve as a whole
Breakdown of or external flashover across common electrical equipment associated with more
than one thyristor level of the valve, or disruptive discharge in dielectric material forming part
of the valve structure, cooling ducts, light guides or other insulating parts of the pulse
transmission and distribution system shall not be permitted.
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