SIST EN 61975:2010

SLOVENSKI STANDARD
SIST EN 61975:2010
01-november-2010
Visokonapetostne enosmerne inštalacije (HVDC) - Sistemski preskusi (IEC
61975:2010)
High-voltage direct current (HVDC) installations - System tests (IEC 61975:2010)
Anlagen zur Hochspannungsgleichstromübertragung (HGÜ) - Systemprüfungen (IEC
61975:2010)
Installations en courant continu à haute tension (CCHT) - Essais système (CEI
61975:2010)
Ta slovenski standard je istoveten z: EN 61975:2010
ICS:
29.130.10 Visokonapetostne stikalne in High voltage switchgear and
krmilne naprave controlgear
SIST EN 61975:2010 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61975:2010

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SIST EN 61975:2010

EUROPEAN STANDARD
EN 61975

NORME EUROPÉENNE
September 2010
EUROPÄISCHE NORM

ICS 29.130.10; 31.080.01


English version


High-voltage direct current (HVDC) installations -
System tests
(IEC 61975:2010)


Installations en courant continu  Anlagen zur
à haute tension (CCHT) - Hochspannungsgleichstromübertragung
Essais système (HGÜ) -
(CEI 61975:2010) Systemprüfungen
(IEC 61975:2010)




This European Standard was approved by CENELEC on 2010-09-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61975:2010 E

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SIST EN 61975:2010
EN 61975:2010 - 2 -
Foreword
The text of document 22F/221/FDIS, future edition 1 of IEC 61975, prepared by SC 22F, Power
electronics for electrical transmission and distribution systems, of IEC TC 22, Power electronic systems
and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 61975 on 2010-09-01.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2011-06-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2013-09-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61975:2010 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC/TR 60919-1 NOTE  Harmonized as CLC/TR 60919-1.
IEC 61000-4-3 NOTE  Harmonized as EN 61000-4-3.
IEC 61803 NOTE  Harmonized as EN 61803.
__________

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SIST EN 61975:2010
- 3 - EN 61975:2010
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60633 1998 Terminology for high-voltage direct current EN 60633 1999
(HVDC) transmission


1)
IEC/TR 60919-2 2008 Performance of high-voltage direct current CLC/TR 60919-2 201X
(HVDC) systems with line-commutated
converters -
Part 2: Faults and switching





1)
At draft stage.

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SIST EN 61975:2010

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SIST EN 61975:2010
IEC 61975
®
Edition 1.0 2010-07
INTERNATIONAL
STANDARD


High-voltage direct current (HVDC) installations – System tests


INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XC
ICS 29.130.10; 31.080.01 ISBN 978-2-88912-100-7
® Registered trademark of the International Electrotechnical Commission

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SIST EN 61975:2010
– 2 – 61975 © IEC:2010(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references.7
3 Terms and definitions .7
3.1 Test classifications terms .7
3.2 Operation state terms .8
4 General .9
4.1 Purpose.9
4.2 Structure of the HVDC system .10
4.3 Structure of the control and protection system.11
4.4 Logical steps of system test.12
4.5 Structure of system test .13
4.6 Precondition for site test .13
5 Converter station test.16
5.1 General .16
5.2 Converter unit test .17
5.3 Energizing of reactive components.18
5.4 Changing the d.c. system configuration.19
5.5 Electromagnetic compatibility.20
5.6 Trip test.21
5.7 Open line test .22
5.8 Back-to-back test.24
5.9 Short circuit test .25
6 Transmission tests.26
6.1 Low power transmission tests .26
6.2 Operator control mode transfer .34
6.3 Changes of d.c. configuration .40
6.4 Main circuit equipment switching.43
6.5 Dynamic performance testing.47
6.6 AC and d.c. system staged faults .56
6.7 Loss of telecom, auxiliaries or redundant equipment .60
6.8 High power transmission tests .63
6.9 Acceptance tests .67
7 Trial operation .74
7.1 General .74
7.2 Purpose of test .74
7.3 Test precondition.74
7.4 Test procedure .74
7.5 Test acceptance criteria.75
8 System test plan and documentation .75
8.1 General .75
8.2 Plant documentation and operating manual.75
8.3 System study reports and technical specification.75
8.4 Inspection and test plan.76
8.5 System test program.76

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8.6 Test procedure for each test .77
8.7 Documentation of system test results.77
8.8 Deviation report .78
Bibliography .79

Figure 1 – Relation among five major aspects of system test .10
Figure 2 – Structure of the HVDC system .11
Figure 3 – Structure of the HVDC control and protection.11
Figure 4 – Structure of system test .15
Figure 5 – Sequence for low power transmission tests.28
Figure 6 – Step response test of current control at the rectifier .49
Figure 7 – Step response test of extinction angle control at the inverter .50
Figure 8 – Step response test of d.c. voltage control at the inverter .50
Figure 9 – Step response test of current control at the inverter .51
Figure 10 – Step response test of power control at the rectifier .51

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SIST EN 61975:2010
– 4 – 61975 © IEC:2010(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

HIGH-VOLTAGE DIRECT CURRENT (HVDC) INSTALLATIONS –
SYSTEM TESTS


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61975 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 first version of IEC 61975 cancels and replaces IEC/PAS 61975 published jointly in 2004
by IEC and CIGRÉ. It constitutes a technical revision incorporating engineering experience.
The text of this standard is based on the following documents:
FDIS Report on voting
22F/221/FDIS 22F/227/RVD

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.

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SIST EN 61975:2010
61975 © IEC:2010(E) – 5 –
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version may be issued at a later date.

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SIST EN 61975:2010
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INTRODUCTION
The standard is structured in eight clauses:
a) Clause 1 – Scope
b) Clause 2 – Normative references
c) Clause 3 – Definitions
d) Clause 4 – General
e) This clause addresses the purpose of this standard, the HVDC system structure, the
control and protection structure, the logical steps of commissioning, the structure of the
system test and that of the system commissioning standard.
f) Clause 5 – Converter station test
g) This clause addresses the commissioning of converter units and verifies the steady state
performance of units as well as switching tests.
h) Clause 6 – Power transmission tests
i) This clause concerns the commissioning of the transmission system, and verifies station
coordination, steady-state and dynamic performance, interference, as well as interaction
between the d.c. and a.c. systems.
j) Clause 7 – Trial operation
k) After completion of the system test, the period of trial operation is normally specified to
verify the normal transmission.
l) Clause 8 – System test plan and documentation
Clauses 5 to 7 comprise individual sections providing an introduction and covering objects,
preconditions and procedures and general acceptance criteria as well as detailed descriptions
of the individual tests.

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SIST EN 61975:2010
61975 © IEC:2010(E) – 7 –
HIGH-VOLTAGE DIRECT CURRENT (HVDC) INSTALLATIONS –
SYSTEM TESTS



1 Scope
This International Standard applies to system tests for high-voltage direct current (HVDC)
installations which consist of a sending terminal and a receiving terminal, each connected to an
a.c. system.
The tests specified in this standard are based on bidirectional and bipolar high-voltage direct
current (HVDC) installations which consist of a sending terminal and a receiving terminal, each
connected to an a.c. system. The test requirements and acceptance criteria should be agreed
for back-to-back installations, while multi-terminal systems and voltage sourced converters are
not included in this standard. For monopolar HVDC installations, the standard applies except
for bipolar tests.
For the special functions or performances that are claimed by specific projects, some extra test
items not included in this standard should be added according to the technical specification
requirements.
This standard only serves as a guideline to system tests for high-voltage direct current (HVDC)
installations. The standard gives potential users guidance, regarding how to plan
commissioning activities. The tests described in the guide may not be applicable to all projects,
but represent a range of possible tests which should be considered.
Therefore, it is preferable that the project organization establishes the individual test program
based on this standard and in advance assigns responsibilities for various tasks/tests between
involved organisations (e.g. user, supplier, manufacturer, operator, purchaser etc.) for each
specific project.
2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For updated references, the latest edition of
the referenced document (including any amendments) applies.
IEC 60633:1998, Terminology for high-voltage direct current (HVDC) power transmission
IEC/TR 60919-2:2008, Performance of high-voltage direct current (HVDC) systems with line
commutated converters – Part 2: Faults and switching
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60633 as well as the
following terms and definitions apply.
3.1 Test classifications terms
3.1.1
station test
converter system test including items which verify the function of individual equipment of the
converter staton in energized state

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SIST EN 61975:2010
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3.1.2
system test
test verifying functions and performances of HVDC system as a whole as well as the interaction
with adjacent a.c. systems
3.1.3
transmission tests
test verifying functions and performances of HVDC system when transmitting power between
both terminals
NOTE It is also referred to as an “end to end test”.
3.2 Operation state terms
In the d.c. system, there are 5 defined states: earthed, stopped, standby, blocked, de-blocked.
3.2.1
earthed
state in which the pole or converter is isolated and earthed on the a.c. and d.c. sides and no
energizing of the pole or converter equipment is possible
NOTE The earthed state provides the necessary safety for carrying out maintenance work, and is the only one that
permits the pole or converter maintenance. In this state maintenance work is possible on the converter transformers,
the isolated and earthed part of the a.c. high voltage bus equipment, d.c. and valve hall installed equipment of this
pole or converter.
3.2.2
stopped/isolated
state in which the pole or converter is isolated from the a.c. and d.c. side, but all the earthing
switches are open
NOTE In this state the d.c. yard can be prepared for power transmission (earth electrode line, pole and d.c. line
connect).
3.2.3
standby
state which is to be used when the d.c. system is not being utilized but is ready for power
transmission
NOTE In this state the converter transformer is to be ready; tap-changer is automatically brought to the start
position, which ensures that the transformer will be energized with minimum voltage to minimize the inrush current.
The disconnector of the a.c. bay should be closed, but the circuit breakers in the feeding bay of the converter
transformer should be open. In this state the d.c. configuration can still be changed (earth electrode line, pole and
d.c. line connect).
3.2.4
blocked
state in which the pole is prepared to transmit power at a moment’s notice
NOTE The converter transformer is connected to the energized a.c. bus by means of closing of the respective
circuit breaker. The valve cooling system is ready for operation if the cooling water conductivity, flow and
temperature are within the specified limits. A defined d.c. configuration shall have been established. Further
changes are not possible in this state. The thyristor pre-check is carried out after the converter transformer has
been energized. The pre-check is considered as passed when in every valve the redundancy is not lost. To change
the blocked state, the states stopped, standby and de-blocked are selectable.
3.2.5
de-blocked
state representing the following two operating modes: power transmission and open line test
NOTE Power transmission is the normal operating mode. In the de-blocked status the pole transmits power in
normal operating mode if both terminals are in the deblocked stage and there is a voltage difference between the
terminals. A minimum number of a.c. filters should be available.

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SIST EN 61975:2010
61975 © IEC:2010(E) – 9 –
3.2.6
off-site tests
tests which are performed before on-site testing
4 General
4.1 Purpose
System test completes the commissioning of an HVDC system.
The supplier can verify the suitability of the station equipment installed and the functional
completeness of the system. Moreover, adjustments and optimizations can be made.
It is shown for the user that the requirements and stipulations in the contract are met and that
there is correlation with studies and previous off-site tests.
For the user, the completion of system test marks the beginning of commercial operation of the
HVDC system.
When adapting the HVDC system to the connected a.c. systems, there may be various
constraints which require coordination within the economic schedules of the a.c. system
operators. System tests prove to the public that tolerable values of phenomena concerning the
public interest are not exceeded.
Five major aspects are subject to system tests:
a) HVDC station equipment and d.c. line/cable/bus including earth electrode, if any;
b) HVDC control and protection equipment and their settings;
c) environmental considerations;
d) a.c./d.c. system interaction;
e) system performance when jointly operated with a connected a.c. system.
The interrelation between these aspects is shown in Figure 1.

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SIST EN 61975:2010
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IEC  1895/10

Figure 1 – Relation among five major aspects of system test
Thorough and complete system test of the above components can be achieved with the tests
described in the standard.
Acceptance tests shall be defined between supplier and user in advance and may be
performed at an appropriate time during the test schedule.
System tests may affect more than the actual contract parties. Those parties shall be informed
in time.
The complexity and the diversified areas concerned during system test require thorough
planning and scheduling, cooperation of all involved parties, as well as complete and organized
documentation.
NOTE The suggested “Test Procedures” are recommendations and alternative test procedures may be used
subject to the agreement between supplier and user.
4.2 Structure of the HVDC system
From a functional point of view an HVDC system consists of a sending terminal and a receiving
terminal, each connected to an a.c. system. The two terminals have one or several converters
connected in series on the d.c. side and in parallel on the a.c. side. The terminals are
connected by a transmission line or cable or a short piece of busbar (back-to-back station).
Multi-terminal systems are not addressed in this standard.
The structure of the HVDC system is shown in Figure 2.

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61975 © IEC:2010(E) – 11 –

IEC  1896/10
Figure 2 – Structure of the HVDC system
4.3 Structure of the control and protection system
Each of the converter units can be controlled individually. To make the system function
correctly as a power transmission system, the converter units should be controlled in a
coordinated way by a higher level of the control system. Coordinated controls and protection
are essential for the proper functioning of HVDC systems.
The structure of the HVDC control and protection is shown in Figure 3:

IEC  1897/10
Figure 3 – Structure of the HVDC control and protection

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SIST EN 61975:2010
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4.4 Logical steps of system test
To ensure proper functioning, the type test and functional performance test should be
conducted in factory in order to debug and test the control system before the site test.
In order to provide the power grid data and help to compile the system test plan, the off-line
digital simulation should be conducted before and during the simulation test, especially
analysis on the power flow, stability and overvoltage.
Considering the complexity of the HVDC system, all limiting design cases may be conducted on
the digital simulator in a similar way to those done on site.
Commissioning an HVDC system may affect more than the actual contract parties. The
complexity and the diversified areas concerned during system test require thorough planning
and scheduling, cooperation of all involved parties and complete and structured documentation.
Before a system test can begin on site, the following preconditions should be fulfilled
concerning subsystem tests, operator training and safety instructions, system test plan and test
procedures, and all necessary test equipment.
a) All subsystems should have been tested and commissioned, including a.c. filters and the
converter transformers with special attention to possible transformer or a.c. filter resonance
during energizing.
b) Operating pe
...