IEC PAS 61975:2004

PUBLICLY
IEC
AVAILABLE
PAS 61975
SPECIFICATION
First edition
Pre-Standard
2004-08
System tests for high-voltage
direct current (HVDC) installations

Reference number
IEC/PAS 61975:2004(E)
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PUBLICLY
IEC
AVAILABLE
PAS 61975
SPECIFICATION
First edition
Pre-Standard
2004-08
System tests for high-voltage
direct current (HVDC) installations

” IEC 2004  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
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For price, see current catalogue

– 2 – PAS 61975 © IEC:2004 (E)

CONTENTS
Part 0: Executive Summary. 4

Part 1: General. 11

1.1 Statement of Purpose . 13

1.2 Structure of the HVDC System. 15

1.3 Structure of the Control and Protection System. 16
1.4 Logical Steps of Commissioning . 17
1.5 Structure of System Testing. 19
Part 2: Off-Site Tests. 20
2.1 Steady State Performance of the Controls . 23
2.1.1 Measurements.24
2.1.2 Control and Protective Sequences. 24
2.1.3 Steady Stale Performance Tests. 25
2.2 Dynamic Performance Tests. 27
2.2.1 Controls-Step Responses . 29
2.2.2 Control Mode Transfer. 31
2.2.3 AC System Interaction/Control. 33
2.2.4 Commutation Failures and Valve Misfires . 34
2.2.5  AC Filter, Transformer and Reactive Element Switching. 36
2.2.6 AC and DC System Faults . 37
2.2.7 Islanding.41
2.3 Functional Performance Tests . 43
2.4  Type Tests on the Control and Protection Equipments . 46
Part 3: Converter Tests . 50
3.1 Converter Unit Tests . 52
3.2 Converter Station Tests. 54

3.2.1 HV Energization or AC Filters, Capacitor Banks and Shunt Reactors . 54
3.2.2 Open Line Test of the DC Switchyard. 55
3.2.3  Load Tests. 57
3.3 Open Line Tests on the DC Transmission Circuit. 61
Part 4: End-to-End-Tests. 63
4.1 Changing the DC System Configuration, Off Voltage . 67
4.2 Start and Stop Sequences and Steady State Operation at Minimum
Power.69
4.3 Protective Blocking and Tripping Sequences . 73
4.4 Power and Current Ramping . 76
4.5 Reduced Voltage Operation. 78

PAS 61975 © IEC:2004 (E) – 3 –

Part 5: Steady-State Performance and Interference Tests. 81

5.1 Harmonic Performance and Filter Components Rating . 83

5.2 Audible Noise . 86

5.3 Overload/Temperature Rise . 88

5.4 Interference .90

5.5 Earth Electrode. 92

Part 6: Operation and Integration Tests . 9

6.1 Changes of DC Configuration. 98
6.1.1 Tests from Monopolar Metallic Return Operation. 100
6.1.2 Tests from Monopolar Earth Return Mode. 101
6.1.3 Tests from Bipolar Operation . 101
6.2 Control Performance. 103
6.2.1 Step Response . 105
6.2.2 Control Mode Transfer. 110
6.2.3 AC System Interaction / Control. 113
6.2.4 Commutation Failure . 116
6.3 Switching AC Side Fillers and Transformers. 119
6.4 Loading Tests. 121
6.5 AC and DC System Staged Fault Tests. 124
6.6 Loss of Telecommunications, Auxiliaries, or Redundant Equipment 129
6.6.1 Loss of Telecommunications between Terminals . 129
6.6.2 Loss of Auxiliary Power Supplies. 132
6.6.3 Loss of Redundant Equipment. 134
Part 7: Trial Operation. 135
Part 8:  System Test Plan and Documentation. 138
8.1 Plant Documentation and Operating Manuals . 139
8.2 System Study Reports and Technical Specifications . 139
8 3 Inspection and Test Plan . 139
8.4 System Test Program . 141
8.5 Test Procedures for each Test. 142

8.6 Documentation of System Test Results. 142
8.7 Deviation Reports. 143

– 4 – PAS 61975 © IEC:2004 (E)

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
SYSTEM TESTS FOR HIGH-VOLTAGE DIRECT CURRENT (HVDC)

INSTALLATIONS
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-
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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
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interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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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.
A PAS is a technical specification not fulfilling the requirements for a standard but made
available to the public.
IEC-PAS 61975 was submitted by the CIGRÉ (International Council on Large Electric
Systems) and has been processed by subcommittee 22F: Power electronics for electrical
transmission and distribution systems, of IEC technical committee 22: Power electronic systems
and equipment.
The text of this PAS is based on the This PAS was approved for
following document: publication by the P-members of the
committee concerned as indicated in
the following document
Draft PAS Report on voting
22F/96/NP 22F/101/RVN
Following publication of this PAS, which is a pre-standard publication, the technical committee
or subcommittee concerned will transform it into an International Standard.

PAS 61975 © IEC:2004 (E) – 5 –

An IEC-PAS licence of copyright and assignment of copyright has been signed by the IEC and
CIGRÉ and is recorded at the Central Office.

This PAS shall remain valid for an initial maximum period of three years starting from 2004-
08. The validity may be extended for a single three-year period, following which it shall be

revised to become another type of normative document or shall be withdrawn.

– 6 – PAS 61975 © IEC:2004 (E)

PART 0: EXECUTIVE SUMMARY
Abstract
This document which gives guidance on all aspects of system tests for HVDC

installations (excluding multiterminal HVDC systems), has been prepared by

CIGRE WG 14.12. It is structured in eight parts.

The guide should give potential users guidance, regarding which course of
action should be taken in planning commissioning activities.
Structure of the tests and a brief statement of the purpose of the individual group
of tests is presented.
Introduction
Commissioning an
...