prEN IEC 60071-12:2021
(Main)Insulation co-ordination - Part 12: Application guidelines for LCC HVDC converter stations (Proposed horizontal standard)
Insulation co-ordination - Part 12: Application guidelines for LCC HVDC converter stations (Proposed horizontal standard)
Isolationskoordination für HVDC Systeme – Teil 12: Anwendungsrichtlinien für Stromrichterstationen mit Stromzwischenkreis-Konverter (LCC)
Koordinacija izolacije - 12. del: Smernice za uporabo LCC visokonapetostnih enosmernih (HVDC) pretvorniških postaj
General Information
Standards Content (sample)
SLOVENSKI STANDARD
oSIST prEN IEC 60071-12:2021
01-november-2021
Koordinacija izolacije - 12. del: Smernice za uporabo LCC visokonapetostnih
enosmernih (HVDC) pretvorniških postaj
Insulation co-ordination - Part 12: Application guidelines for LCC HVDC converter
stationsTa slovenski standard je istoveten z: prEN IEC 60071-12:2021
ICS:
29.080.30 Izolacijski sistemi Insulation systems
oSIST prEN IEC 60071-12:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN IEC 60071-12:2021
99/326/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60071-12 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2021-09-24 2021-12-17
SUPERSEDES DOCUMENTS:
99/308/CD, 99/315/CC
IEC TC 99 : INSULATION CO-ORDINATION AND SYSTEM ENGINEERING OF HIGH VOLTAGE ELECTRICAL POWER INSTALLATIONS ABOVE
1,0 KV AC AND 1,5 KV DCSECRETARIAT: SECRETARY:
Australia Ms Erandi Chandrasekare
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
TC 8,SC 22F,TC 115
Other TC/SCs are requested to indicate their interest, if any, in
this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel votingThe attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which
they are aware and to provide supporting documentation.TITLE:
Insulation co-ordination - Part 12: Application guidelines for LCC HVDC converter stations
PROPOSED STABILITY DATE: 2028NOTE FROM TC/SC OFFICERS:
Copyright © 2021 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
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oSIST prEN IEC 60071-12:2021
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1 CONTENTS
3 FOREWORD ........................................................................................................................... 5
4 1 General ........................................................................................................................... 8
5 1.1 Scope ..................................................................................................................... 8
6 1.2 Additional background ............................................................................................ 8
7 2 Normative references ...................................................................................................... 8
8 3 Terms, definitions, symbols and abbreviations ................................................................. 9
9 3.1 Terms and definition ............................................................................................... 9
10 3.2 Symbols and abbreviation ....................................................................................... 9
11 3.2.1 General ........................................................................................................... 9
12 3.2.2 Subscripts ..................................................................................................... 10
13 3.2.3 Letter symbols ............................................................................................... 10
14 3.2.4 Abbreviations................................................................................................. 10
15 4 Typical LCC HVDC converter station schemes .............................................................. 11
16 5 Voltages and overvoltages in service ............................................................................. 13
17 5.1 Continuous operating voltages at various locations in the converter station .......... 13
18 5.2 Peak continuous operating voltage (PCOV) and crest continuous operating19 voltage (CCOV) .................................................................................................... 17
20 5.3 Sources and types of overvoItages ....................................................................... 18
21 5.4 Temporary overvoltage ......................................................................................... 19
22 5.4.1 General ......................................................................................................... 19
23 5.4.2 Temporary overvoltage on the a.c. side ......................................................... 19
24 5.4.3 Temporary overvoltages on the d.c. side ....................................................... 20
25 5.5 Slow-front overvoltages ........................................................................................ 20
26 5.5.1 General ......................................................................................................... 20
27 5.5.2 Slow-front overvoltages on the a.c. side ........................................................ 20
28 5.5.3 Slow-front overvoltages on the d.c. side ........................................................ 21
29 5.6 Fast-front, very-fast-front and steep-front overvoltages ......................................... 21
30 6 Arrester characteristics and stresses ............................................................................. 22
31 6.1 Arrester characteristics ......................................................................................... 22
32 6.2 Arrester specification ............................................................................................ 23
33 6.3 Arrester stresses .................................................................................................. 24
34 6.3.1 General ......................................................................................................... 24
35 6.3.2 AC bus arrester (A) ........................................................................................ 24
36 6.3.3 AC filter arrester (FA) .................................................................................... 25
37 6.3.4 Transformer valve winding arresters (T) ........................................................ 25
38 6.3.5 Valve arrester (V) .......................................................................................... 25
39 6.3.6 Bridge arrester (B) ......................................................................................... 28
40 6.3.7 Converter unit arrester (C) ............................................................................. 29
41 6.3.8 Mid-point d.c. bus arrester (M) ....................................................................... 29
42 6.3.9 Converter unit d.c. bus arrester (CB) ............................................................. 29
43 6.3.10 DC bus and d.c. line/cable arrester (DB and DL/DC) ...................................... 30
44 6.3.11 Neutral bus arrester (E, EL, EM in Figure 3, EB, E1, EL, EM in Figure 1) ...... 30
45 6.3.12 DC reactor arrester (DR) ............................................................................... 31
46 6.3.13 DC filter arrester (FD) .................................................................................... 32
47 6.3.14 Earth electrode station arrester ..................................................................... 32
48 6.4 Protection strategy ................................................................................................ 32
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49 6.4.1 General ......................................................................................................... 32
50 6.4.2 Insulation directly protected by a single arrester ............................................ 32
51 6.4.3 Insulation protected by more than one arrester in series ................................ 32
52 6.4.4 Valve side neutral point of transformers ......................................................... 33
53 6.4.5 Insulation between phase conductors of the converter transformer ................ 33
54 6.4.6 Summary of protection strategy ..................................................................... 33
55 6.5 Summary of events and stresses .......................................................................... 35
56 7 Design procedure of insulation co-ordination ................................................................. 36
57 7.1 General ................................................................................................................. 36
58 7.2 Arrester requirements ........................................................................................... 36
59 7.3 Representative overvoltages (U ) ........................................................................ 37
60 7.4 Determination of the co-ordination withstand voltages (U )................................. 39
61 7.5 Determination of the required withstand voltages (U ) ........................................ 39
62 7.6 Determination of the specified withstand voltage (U ) .......................................... 39
63 8 Study tools and system modelling .................................................................................. 39
64 8.1 General ................................................................................................................. 39
65 8.2 Study approach and tooIs ..................................................................................... 39
66 8.3 System details ...................................................................................................... 40
67 8.3.1 Modelling and system representation ............................................................. 40
68 8.3.2 AC network and a.c. side of the LCC HVDC converter station ........................ 41
69 8.3.3 DC overhead line/cable and earth electrode line details ................................. 42
70 8.3.4 DC side of an LCC HVDC converter station details ........................................ 42
71 Annex A (informative) Example of insulation co-ordination for LCC HVDC converter
72 stations ......................................................................................................................... 44
73 A.1 Introduction ........................................................................................................... 44
74 A.2 Example for LCC HVDC converter station in a pole with one 12-pulse75 converter .............................................................................................................. 44
76 A.2.1 Arrester protective scheme ............................................................................ 44
77 A.2.2 Arrester stresses, protection and insulation levels ......................................... 44
78 A.2.3 Transformer valve side withstand voltages .................................................... 48
79 A.2.4 Air-insulated smoothing reactors withstand voltages ...................................... 49
80 A.2.5 Results .......................................................................................................... 50
81 A.3 Example for LCC HVDC converter station in a pole with two 12-pulse82 converters in series............................................................................................... 52
83 A.3.1 Arrester protective scheme ............................................................................ 52
84 A.3.2 Arrester stresses, protection and insulation levels ......................................... 53
85 A.3.3 Transformer valve side withstand voltages .................................................... 57
86 A.3.4 Smoothing reactor withstand voltages............................................................ 58
87 A.3.5 Results .......................................................................................................... 60
88 Bibliography .......................................................................................................................... 62
90 Figure 1 – Possible arrester locations in a pole with two 12-pulse converters in series ......... 12
91 Figure 2 – Possible arrester locations for a back-to-back converter station ........................... 13
92 Figure 3 – LCC HVDC converter station in a pole with one 12-pulse converter ...................... 14
93 Figure 4 – Continuous operating voltages at various locations (location identification
94 according to Figure 3) ........................................................................................................... 16
95 Figure 5 – Operating voltage of a valve arrester (V), rectifier operation ................................. 18
96 Figure 6 – Operating voltage of a mid-point arrester (M), rectifier operation .......................... 18
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97 Figure 7 – Operating voltage of a converter bus arrester (CB), rectifier operation ................. 18
98 Figure 8 – One pole of an LCC HVDC converter station ........................................................ 41
99 Figure A.1 – AC and DC arresters (LCC HVDC converter station in a pole with one 12-
100 pulse converter) .................................................................................................................... 51
101 Figure A.2 – Valve arrester stresses for slow-front overvoltages from a.c. side ..................... 51
102 Figure A.3 – Arrester V2 stress for slow-front overvoltage from a.c. side .............................. 51
103 Figure A.4 – Valve arrester stresses for earth fault between valve and upper bridge
104 transformer bushing .............................................................................................................. 52
105 Figure A.5 – Arrester V1 stress for earth fault between valve and upper bridge
106 transformer bushing .............................................................................................................. 52
107 Figure A.6 – AC and DC arresters (LCC HVDC converter station in a pole with two 12-
108 pulse converters in series) .................................................................................................... 61
109110 Table 1 – Symbol description ................................................................................................ 13
111 Table 2 – Arrester protection on the d.c. side: one 12-pulse converter (Figure 3) .................. 33
112 Table 3 – Arrester protection on the d.c. side: two 12-pulse converters in series
113 (Figure1) ............................................................................................................................... 34
114 Table 4 – Events stressing arresters: one 12-pulse converter (Figure 3) ............................... 35
115 Table 5 – Types of arrester stresses for different events: one 12-pulse converter
116 (Figure 3) .............................................................................................................................. 36
117 Table 6 – Arrester requirements ............................................................................................ 37
118 Table 7 – Representative overvoltages and required withstand voltages ............................... 37
119 Table 8 – Origin of overvoltages and associated frequency ranges ....................................... 40
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121 INTERNATIONAL ELECTROTECHNICAL COMMISSION
122 ____________
123
124 INSULATION CO-ORDINATION
125
126 Part 12: Application guidelines for LCC HVDC converter stations
127
128
129
130 FOREWORD
131 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
132 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
133 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
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139 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
140 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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142 interested IEC National Committees.143 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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145 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
146 misinterpretation by any end user.147 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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150 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
151 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
152 services carried out by independent certification bodies.153 6) All users should ensure that they have the latest edition of this publication.
154 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
155 members of its technical committees and IEC National Committees for any personal injury, property damage or
156 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
157 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
158 Publications.159 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
160 indispensable for the correct application of this publication.161 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
162 rights. IEC shall not be held responsible for identifying any or all such patent rights.
163 IEC 60071-12 has been prepared by IEC technical committee 99: Insulation co-ordination and
164 system engineering of high voltage electrical power installations above 1,0 kV AC and 1,5 kV
165 DC. It is an International Standard.166 This International Standard and IEC 60071-11 'Definitions, principles and rules for HVDC
167 system' jointly replace IEC 60071-5 published in 2014.168 The sections arrangement of this standard and corresponding section of IEC 60071-5: 2014 are
169 as follows,IEC 60071-12 IEC 60071-5:2014
1 General 1
1.1 Scope 1.1
1.2 Additional background 1.2
2 Normative references 2
3 Terms, definitions, symbols and abbreviations -
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3 .1 Terms and definitions 3
3.2 Symbols and abbreviations 4
3.2.1 General 4.1
3.2.2 Subscripts 4.2
3.2.3 Letter symbols 4.3
3.2.4 Abbreviations 4.4
4 Typical LCC HVDC converter station schemes 5
5 Voltages and overvoltages in service 7
5.1 Continuous operating voltages at various locations in the 7.1
converter station
5.2 Peak continuous operating voltage (PCOV) and crest continuous 7.2
operating voltage (CCOV)
5.3 Sources and types of overvoItages 7.3
5.4 Temporary overvoltage 7.4
5.5 Slow-front overvoltages 7.5
5.6 Fast-front, very-fast-front and steep-front overvoltages 7.6
6 Arrester characteristics stresses 8
6.1 Arresters characteristics 8.1
6.2 Arresters specification 8.2
6.3 Arrester stresses 8.3
6.4 Protection strategy 8.4
6.5 Summary of events and stresses 8.5
7 Design procedure of insulation co-ordination 9
7.1 General 9.1
7.2 Arrester requirements 9.2
7.3 Representative overvoltages (U ) 9.4
7.4 Determination of the co-ordination withstand voltages 9.5
(U )
7.5 Determination of the required withstand voltages (U ) 9.6
7.6 Determination of the specified withstand voltage (U ) 9.7
8 Study tools and system modelling 10
8.1 General 10.1
8.2 Study approach and tools 10.2
8.3 System details 10.3
Annex A (informative) Example of insulation co-ordination for LCC Annex A (informative) Example
HVDC converter stations of insulation co-ordination forconventional HVDC converters
170 The text of this International Standard is based on the following documents:
FDIS Report on voting
xx/xx/FDIS xx/xx/RVD
171 Full information on the voting for the approval of this International Standard can be found in the
172 report on voting indicated in the above table.173 The language used for the development of this International Standard is English.
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174 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
175 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
176 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
177 described in greater detail at http://www.iec.ch/standardsdev/publications.178 The committee has decided that the contents of this document will remain unchanged until the
179 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
180 specific document. At this date, the document will be181 • reconfirmed,
182 • withdrawn,
183 • replaced by a revised edition, or
184 • amended.
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185 INSULATION CO-ORDINATION
186
187 Part 12: Application guidelines for LCC HVDC converter stations
188
189
190
191 1 General
192 1.1 Scope
193 This standard applies guidelines on the procedures for insulation co-ordination of line
194 commutated converter (LCC) stations for high-voltage direct current (HVDC) project, whose aim
195 is to give guidance for the determination of the specified withstand voltages for equipment.
196 The content of this document strictly follows the flow chart of the insulation co-ordination
197 process and give detailed information on the concepts governing the insulation co-ordination
198 process which leads to the establishment of the specified withstand voltage levels.
199 This document emphasizes the necessity of considering, at the very beginning, all origins, all
200 classes and all types of voltage stresses in service. At the end of the process, when the
201 selection of the specified withstand voltages takes place, does the principle of covering a
202 particular service voltage stress by a specified withstand voltage apply.203 The annex contains examples of insulation co-ordination for LCC HVDC converters which
204 support the concepts described in the main text, and the basic analytical techniques used.
205 1.2 Additional background206 The use of power semi-conductor device in a series and/or parallel arrangement, along with the
207 unique control and protection strategies employed in the conversion process, has ramifications
208 requiring particular consideration of overvoltage protection of equipment in converter stations
209 compared with substations in a.c. systems. This standard outlines the procedures for evaluating
210 the overvoltage stresses on the converter station equipment subjected to combined d.c., a.c.
211 power frequency, harmonic and impulse voltages. The criteria for determining the protective
212 levels of series and/or parallel combinations of surge arresters used to ensure optimal
213 protection are also presented.214 Concerning surge arrester protection, this standard deals only with metal-oxide surge arresters,
215 without gaps, which are used in modern HVDC converter stations. The basic arrester
216 characteristics, requirements for these arresters and the process of evaluating the maximum
217 overvoltages to which they may be exposed in service, are presented. Typical arrester
218 protection schemes and stresses of arresters are presented, along with methods to be applied
219 for determining these stresses.220 This standard discusses insulation co-ordination related to line commutated converter (LCC)
221 HVDC converter stations. The insulation coordination of voltage sourced converters (VSC) is
222 not part of this standard.223 2 Normative references
224 The following documents are referred to in the text in such a way that some or all of their content
225 constitutes requirements of this document. For dated references, only the edition cited applies.
226 For undated references, the latest edition of the referenced document (including any
227 amendments) applies.228 IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
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229 IEC 60071-1:2019, Insulation co-ordination – Part 1: Definitions, principles and rules
230 IEC 60071-2:2018, Insulation co-ordination – Part 2: Application guide231 IEC 60099-4:2014, Surge arresters – Part 4: Metal-oxide surge arresters without gaps for a.c.
232 systems233 IEC 60099-9:2014, Surge arresters – Part 9: Metal-oxide surge arresters without gaps for HVDC
234 converter stations235 IEC 60633, Terminology for high-voltage direct current (HVDC) transmission
236 IEC TS 60815-1:2008, Selection and dimensioning of high-voltage insulators intended for use
237 in polluted conditions – Part 1: Definitions, information and general principles
238 IEC TS 60815-2:2008, Selection and dimensioning of high-voltage insulators intended for use
239 in polluted conditions – Part 2: Ceramic and glass insulators for a.c. systems
240 IEC TS 60815-3:2008, Selection and dimensioning of high-voltage insulators intended for use
241 in polluted conditions – Part 3: Polymer insulators for a.c. systems242 3 Terms, definitions, symbols and abbreviations
243 3.1 Terms and definition
244 For the purposes of this document, the terms and definitions given in IEC 60071-11 and the
245 following apply.246 ISO and IEC maintain terminological databases for use in standardization at the following
247 addresses:248 • IEC Electropedia: available at http://www.electropedia.org/
249 • ISO Online browsing platform: available at http://www.iso.org/obp
250 3.1.1
251 crest value of continuous operating voltage
252 CCOV
253 highest continuously occurring crest value of the voltage at the equipment on the d.c. side of
254 the converter station excluding commutation overshoots255 3.1.2
256 peak value of continuous operating voltage
257 PCOV
258 highest continuously occurring crest value of the voltage at the equipment on the d.c. side of
259 the converter station including commutation overshoots and commutation notches
260 3.1.3261 thyristor valve protective firing
262 method of protecting the individual thyristors from excessive forward voltage stresses across
263 individual thyristors, by firing them264 3.2 Symbols and abbreviation
265 3.2.1 General
266 The list covers only the most frequently used symbols and abbreviations, some of which are
267 illustrated graphically in the single-line diagram of Figure 1 and Figure 2. For a more complete
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268 list of symbols which has been adopted for LCC HVDC converter stations, and also for insulation
269 co- ordination, refer to the standards listed in the normative references (Clause 2) and to the
270 Bibliography.271 3.2.2 Subscripts
...
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