oSIST prEN IEC 62271-211:2023

SLOVENSKI STANDARD
oSIST prEN IEC 62271-211:2023
01-september-2023
Visokonapetostne stikalne in krmilne naprave - 211. del: Neposredna povezava
med elektroenergetskimi transformatorji in plinsko izoliranimi stikalnimi
napravami v kovinskih ohišjih za naznačene napetosti nad 52 kV
High-voltage switchgear and controlgear - Part 211: Direct connection between power
transformers and gas-insulated metal-enclosed switchgear for rated voltages above 52
kV
Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil 211: Direkte Verbindungen
zwischen Leistungstransformatoren und gasisolierten metallgekapselten Schaltanlagen
für Bemessungsspannungen über 52 kV
Appareillage à haute tension - Partie 211: Raccordements directs entre transformateurs
de puissance et appareillage sous enveloppe métallique à isolation gazeuse de tension
assignée supérieure à 52 kV
Ta slovenski standard je istoveten z: prEN IEC 62271-211:2023
ICS:
29.130.10 Visokonapetostne stikalne in High voltage switchgear and
krmilne naprave controlgear
oSIST prEN IEC 62271-211:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN IEC 62271-211:2023

---------------------- Page: 2 ----------------------
oSIST prEN IEC 62271-211:2023
17C/901/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62271-211 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-07-21 2023-10-13
SUPERSEDES DOCUMENTS:
17C/879/CD, 17C/894/CC

IEC SC 17C : ASSEMBLIES
SECRETARIAT: SECRETARY:
Germany Mr Mark Kuschel
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

TC 14,TC 17,SC 17A,SC 36A
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 voting
The 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.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is
the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
High-voltage switchgear and controlgear - Part 211: Direct connection between power
transformers and gas-insulated metal-enclosed switchgear for rated voltages above 52 kV

PROPOSED STABILITY DATE: 2032

NOTE FROM TC/SC OFFICERS:


Copyright © 2023 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 permission in writing from IEC.

---------------------- Page: 3 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 2 17C/901/CDV
1 CONTENTS
2
3 FOREWORD. 4
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms and definitions . 7
7 4 Normal and special service conditions . 9
8 4.1 Normal service conditions . 9
9 4.2 Special service conditions . 9
10 5 Ratings . 10
11 5.1 General . 10
12 5.2 Rated voltage (U ) . 10
r
13 5.3 Rated insulation level (Ud, Up, Us) . 10
14 5.4 Rated frequency (f ) . 10
r
15 5.5 Rated continuous current (I ) . 10
r
16 5.6 Rated short-time withstand current (I ) and rated thermal short-time
k
17 current (I ) . 10
th
18 5.7 Rated peak withstand current (I ) and rated dynamic current (I ) . 11
p d
19 5.8 Rated duration of short-circuit (t ) and of thermal short-time current (t ) . 11
k th
20 6 Design and construction . 11
21 6.1 Gas and vacuum tightness . 11
22 6.2 Gas pressure for insulation of the bushing inside the GIS enclosure . 11
23 6.3 Pressure withstands requirements . 11
24 6.4 Standard dimensions and tolerances . 12
25 6.4.1 General . 12
26 6.4.2 Single-phase direct connection between oil-filled transformer
27 and switchgear . 12
28 6.4.3 Three-phase direct connection between oil-filled transformer
29 and switchgear . 12
30 6.4.4 Connection between gas-insulated transformer and
31 switchgear . 12
32 6.4.5 Transformer tolerances . 12
33 6.4.6 Mounting of the transformer on its foundation . 12
34 6.5 Limits of supply . 13
35 6.6 Mechanical forces applied on the connection interface . 14
36 6.7 Mechanical forces applied on the bushing flange . 14
37 6.8 Horizontal and vertical displacement . 16
38 6.9 Vibrations . 16
39 7 Type tests . 16
40 7.1 General . 16
41 7.2 Dielectric tests . 16
42 7.2.1 Dielectric tests of bushing . 16
43 7.2.2 Dielectric tests of transformer connection in a single-phase
44 enclosure . 17
45 7.2.3 Dielectric tests of transformer connection in a three-phase
46 enclosure . 17
47 7.3 Cantilever loads withstand tests . 17
48 7.4 Gas tightness tests . 17
49 8 Routine tests . 17

---------------------- Page: 4 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 3 17C/901/CDV
50 8.1 General . 17
51 8.2 External pressure test of the bushing . 17
52 8.3 Tightness tests . 18
53 9 Guide to the selection of switchgear and controlgear (informative) . 18
54 10 Information to be given with enquiries, tenders and orders (informative) . 18
55 11 Transport, storage, installation, operating instructions and maintenance . 18
56 12 Safety . 18
57 13 Environmental aspects . 18
58 Bibliography . 23
59
60 Figure 1 – Typical direct connection between power transformer and gas-insulated
61 metal-enclosed switchgear . 19
62 Figure 2 – Standard dimensions for typical direct connection between power
63 transformer and gas-insulated metal-enclosed switchgear . 20
64 Figure 3 – Transformer tolerances for a typical direct connection shown on the
65 example of a three-phase power transformer connected to a single-phase gas-
66 insulated metal-enclosed switchgear . 21
67 Figure 4 – Transformer tolerances for a typical direct connection shown on the
68 example of a three-phase power transformer connected to a three-phase gas-insulated
69 metal-enclosed switchgear up to 170 kV . 22
70
71 Table 1 – Moments and forces applied on the bushing flange and transformer . 15
72
73

---------------------- Page: 5 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 4 17C/901/CDV
74 INTERNATIONAL ELECTROTECHNICAL COMMISSION
75 ____________
76
77 HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
78
79 Part 211: Direct connection between power transformers and gas-
80 insulated metal-enclosed switchgear for rated voltages above 52 kV
81
82 FOREWORD
83 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
84 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
85 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
86 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
87 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
88 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
89 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
90 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
91 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
92 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
93 consensus of opinion on the relevant subjects since each technical committee has representation from all
94 interested IEC National Committees.
95 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
96 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
97 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
98 misinterpretation by any end user.
99 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
100 transparently to the maximum extent possible in their national and regional publications. Any divergence between
101 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
102 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
103 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
104 services carried out by independent certification bodies.
105 6) All users should ensure that they have the latest edition of this publication.
106 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
107 members of its technical committees and IEC National Committees for any personal injury, property damage or
108 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
109 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
110 Publications.
111 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
112 indispensable for the correct application of this publication.
113 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
114 rights. IEC shall not be held responsible for identifying any or all such patent rights.
115 International Standard IEC 62271-211 has been prepared by subcommittee 17C: High-voltage
116 switchgear and controlgear assemblies, of IEC technical committee 17: Switchgear and
117 controlgear.
118 This second edition cancels and replaces the first edition of IEC 62271-211:2014, COR1:2015
119 and COR2:2017 and constitutes a technical revision.
120 This second edition includes the following significant technical changes with respect to the
121 previous edition:
122 • re-numbering of clauses according to IEC 62271-1:2017,
123 • clause 1 (former 1.1): Scope (no modifications)
124 • clause 2 (former clause 1.2): updated dated references,
125 clause 3: updating definition about bushing (3.1), updating some pressure definitions (3.6,
126 3.7, 3.8, 3.9), rewording definition about proctor density (3.11),
127 • clause 4 (former clause 2): updated references,

---------------------- Page: 6 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 5 17C/901/CDV
128 • clause 5 (former clause 4): add a subclause 5.1 General, according to IEC 62271-1:2017
129 and IEC 62271-203:2022,
130 o subclause 5.5: new first paragraph, rewording second paragraph,
131 o subclause 5.8: modify the term “Rated duration of thermal short-time current” of
132 the bushing,
133 • clause 6: restructure and rewording of subclauses:
134 o 6.1 (former 5.3): requirements about gas and vacuum tightness of the
135 transformer bushing
136 o 6.3 (former 5.2): harmonization with IEC 62271-203:2022 about typical
137 maximum pressure in service for SF6, other gases and gas mixtures,
138 o 6.4 (former 8), rewording
139 o 6.5 (former 5.1), some rewording and modification
140 o 6.6 (former 5.4), some rewording, updated references
141 o 6.7 (former 5.5), some rewording
142 o 6.8 (former 5.6), some rewording
143 o 6.9 (former 5.7), slight rewording
144 • clause 7 (former clause 6) type tests: some rewording and clarifications about
145 references,
146 • clause 8 (former clause 7) routine tests:
147 o 8.2 (former 7.2): add a paragraph about SF6-mixtures and other gases than SF6,
148 o 8.3 (former 7.3): update reference to relevant on-site test according to IEC
149 62271-203:2022,
150 • clause 9 Guide to the selection of switchgear and controlgear (new): informative, to
151 have a reference to IEC 62271-203:2022,
152 • clause 10 (former 9) informative: update references
153 • clause 11 (former 10): updated headline and updated reference according to IEC 62271-
154 1:2017,
155 • new clauses 12 Safety and 13 Environmental aspects: Adding of references to safety
156 and environmental aspects,
157 • correction of errors in Corrigendum 2 of IEC 62271-211:2017,
158 • modified orientation of Fig. 1 to Fig. 4 for easier reading the tables,
159 • update references in the Bibliography.
160 The text of this document is based on the following documents:
FDIS Report on voting

161
162 Full information on the voting for the approval of this document can be found in the report on
163 voting indicated in the above table.
164 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
165 A list of all parts in the IEC 62271 series, published under the general title High-voltage
166 switchgear and controlgear, can be found on the IEC website.
167 The committee has decided that the contents of this publication will remain unchanged until the
168 stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
169 the specific publication. At this date, the publication will be
170 • reconfirmed,
171 • withdrawn,

---------------------- Page: 7 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 6 17C/901/CDV
172 • replaced by a revised edition, or
173 • amended.
174
175

---------------------- Page: 8 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 7 17C/901/CDV
176 HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
177
178 Part 211: Direct connection between power transformers and gas-
179 insulated metal-enclosed switchgear for rated voltages above 52 kV
180
181
182
183 1 Scope
184 This part of IEC 62271 is applicable to single- and three-phase direct connections between gas-
185 insulated metal-enclosed switchgear (GIS) for rated voltages above 52 kV and transformer
186 arrangements to establish electrical and mechanical interchange ability and to determine the
187 limits of supply for the transformer connection.
188 Direct connections are immersed on one end in the transformer oil or insulating gas and on the
189 other end in the insulating gas of the switchgear.
190 Transformer arrangements are single-phase transformers with single-phase enclosed
191 arrangement, three-phase transformers with three single-phase enclosed arrangements or
192 three-phase transformers with a three-phase enclosed arrangement with three transformer
193 bushings.
194 The connection satisfies the requirements of IEC 62271-203 for gas-insulated metal-enclosed
195 switchgear, IEC 60076 for power transformer and IEC 60137 for completely immersed
196 bushings.
197 For the purposes of this document the term "switchgear" is used for "gas-insulated metal-
198 enclosed switchgear".
199 2 Normative references
200 The following documents, in whole or in part, are normatively referenced in this document and
201 are indispensable for its application. For dated references, only the edition cited applies. For
202 undated references, the latest edition of the referenced document (including any amendments)
203 applies.
204 IEC 60076 (all parts), Power transformers
205 IEC 60137:2017, Insulated bushings for alternating voltages above 1 000 V
206 IEC 61936-1, Power installations exceeding 1 kV a.c. – Part 1: Common rules
207 IEC 62271-1:2017 and IEC 62271-1:2017/AMD1:2021, High-voltage switchgear and
208 controlgear – Part 1: Common specifications
209 IEC 62271-203:2022, High-voltage switchgear and controlgear – Part 203: Gas-insulated metal-
210 enclosed switchgear for rated voltages above 52 kV
211 IEC 62271-207, High-voltage switchgear and controlgear – Part 207: Seismic qualification for
212 gas-insulated switchgear assemblies for rated voltages above 52 kV
213 3 Terms and definitions
214 For the purposes of this document, the terms and definitions given in IEC 62271-1, as well as
215 the following apply.

---------------------- Page: 9 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 8 17C/901/CDV
216 ISO and IEC maintain terminological databases for use in standardization at the following
217 addresses:
218 • IEC Electropedia: available at http://www.electropedia.org/
219 • ISO Online browsing platform: available at http://www.iso.org/obp
220 3.1
221 bushing
222 device that enables one or several conductors to pass through an enclosure and insulate the
223 conductors from it
224 [SOURCE: IEC 60050-471:2007, 471-02-01, modified – “an enclosure” inserted after “pass
225 through” and “a partition such as a wall or a tank” deleted. Notes 1 and 2 were deleted.]
226 3.2
227 completely immersed bushing
228 bushing, both ends of which are intended to be immersed in an insulating medium other than
229 ambient air (e.g. oil or gas)
230 [SOURCE: IEC 60050-471:2007, 471-02-04]
231 3.3
232 gas-insulated switchgear enclosure
233 part of gas-insulated metal-enclosed switchgear retaining the insulating gas under the
234 prescribed conditions necessary to maintain safely the highest insulation level, protecting the
235 equipment against external influences and providing a high degree of protection to personnel
236 Note 1 to entry: The enclosure can be single-phase or three-phase.
237 [SOURCE: 3.103 of IEC 62271-203:2022]
238 3.4
239 main circuit end terminal
240 part of the main circuit of a gas-insulated metal enclosed switchgear forming part of the
241 connection interface
242 [SOURCE: 3.2 of IEC 62271-209:2019]
243 3.5
244 transformer connection enclosure
245 part of the gas-insulated metal-enclosed switchgear which houses one end of a completely
246 immersed bushing fitted on a power transformer and a main circuit end terminal
247
248 3.6
249 maximum external operating gas pressure
250 maximum pressure of the gaseous insulating medium in which the bushing is partially or
251 completely immersed when in operation
252 Note 1 to entry: It is at least equal to the maximum pressure in the transformer connection enclosure of the GIS at
253 the highest temperature that the gas used for insulation can reach under specified maximum service conditions.
254
255 Note 2 to entry: In case of gas insulated transformers it is also the maximum insulating pressure of the gaseous
256 insulating medium in which the end of the bushing is immersed into the power transformer, when in operation, the
257 bushing-power transformer connection assembly carrying its rating continuous current at the maximum ambient
258 temperature.

---------------------- Page: 10 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 9 17C/901/CDV
259 [SOURCE: 3.32 of IEC 60137:2017, Note 1 to entry and Note 2 to entry were added]
260
261 3.7
262 enclosure design pressure
263 relative pressure used to determine the design of the enclosure
264 Note 1 to entry: It is at least equal to the maximum pressure in the enclosure at the highest temperature that the gas
265 used for insulation can reach under specified maximum service conditions.
266 Note 2 to entry: The transient pressure occurring during and after a breaking operation (e.g. circuit -breaker) is not
267 considered in the determination of the design pressure.
268 [Source: 3.114 of IEC 62271-203:2022]
269
270 3.8
271 filling pressure p for insulation
re
272 filling density ρ for insulation
re
273 pressure (in Pa), for insulation, referred to the standard atmospheric air conditions of +20 °C
274 and 101,3 kPa (or density), which may be expressed in relative or absolute terms, to which the
275 assembly is filled before being put into service
276 [SOURCE: 3.6.5.1 of IEC 62271-1:2017, modified – deleted the terms “and/or switching”,
277 deleted “or automatically replenished”]
278 3.9
279 minimum functional pressure p for insulation
me
280 minimum functional density ρ for insulation
me
281 pressure (in Pa), for insulation, referred to the standard atmospheric air conditions of +20 °C
282 and 101,3 kPa (or density), which may be expressed in relative or absolute terms, at which and
283 above which the characteristics of the switchgear-power-transformer connection are maintained
284 [SOURCE: 3.6.5.5 of IEC 62271-1:2017, modified – deleted the terms “and/or switching”, add
285 “the characteristics of the switchgear-power-transformer connection” deleted “rated
286 characteristics of switchgear and controlgear“]
287 3.10
288 insulated junction
289 all parts which are needed to insulate the transformer from the switchgear including but not
290 limited to the insulating flange
291 3.11
292 proctor density
293 highest dry density of a soil for a given compaction effort depending on the amount of water the
294 soil contains during soil compaction of controlled magnitude according Proctor Standard test
295 Note 1 to entry: Proctor Standard test is defined in ASTM D-698. However, other tests methods exist providing similar
296 information, but not always equivalent, like for example ISO 17892-2, BS 1377, UNE 103500, NF P 94-093 and DIN
297 18127.
298 4 Normal and special service conditions
299 4.1 Normal service conditions
300 Subclause 4.1 of IEC 62271-203:2022 is applicable.
301 4.2 Special service conditions
302 Subclause 4.2 of IEC 62271-203:2022 is applicable.

---------------------- Page: 11 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 10 17C/901/CDV
303 5 Ratings
304 5.1 General
305 When dimensioning a direct connection between a switchgear and a power-transformer the
306 following rated values apply.
307 5.2 Rated voltage (U )
r
308 The rated voltage shall be the rated voltage of the switchgear, selected from the following
309 standard values:
310 72,5 kV – 100 kV – 123 kV – 145 kV – 170 kV – 245 kV – 300 kV – 362 kV – 420 kV – 550 kV
311 NOTE Values 800 kV and higher are not considered because there is little experience at this time.
312 5.3 Rated insulation level (Ud, Up, Us)
313 The rated insulation level for the GIS part in the direct connection enclosure shall comply with
314 the related rated voltage values given in the product standard IEC 62271-203. The rated
315 insulation level for the transformer bushing shall be selected from the values given in the
316 product standard IEC 60137.
317 NOTE Transformers can be tested at other insulation level values, according to the relevant standard.
318 The rated insulation level for a direct connection shall fulfil at least the requirements of
319 IEC 62271-203.
320 5.4 Rated frequency (f )
r
321 Subclause 5.4 of IEC 62271-1:2017 is applicable.
322 5.5 Rated continuous current (I )
r
323 This rating defines the RMS value of the current, the direct connection can carry continuously
324 for its service conditions (see Clause 4).
325 The dimensions of the connection interfaces shown in Figure 2 allow a maximum value of
326 3150 A for the rated continuous current at normal service conditions i.e. maximum ambient
327 temperature of 40°C (see 4.1). The connection interface is shown in Figure 1 as parts 3 and 4.
328 The contact surfaces of the connection interface shall be silver-coated, copper-coated or bare
329 copper.
330 For the rated continuous current, the connection between switchgear and power transformer
331 shall be designed so that the temperature of the transformer connection enclosure and the
332 temperature of the connection interface do not exceed the values given in 7.5.6 of IEC
333 62271- 1:2017.
334 5.6 Rated short-time withstand current (I ) and rated thermal short-time current (I )
th
k
335 For the rated short-time withstand current of the GIS part of the direct connection 5.6 of
336 IEC 62271-1:2017 and for the rated thermal short-time current of the bushing 4.3 of
337 IEC 60137:2017 are applicable.
338 It is recommended to assign the same value for both short-time rated currents for GIS and
339 bushing.

---------------------- Page: 12 ----------------------
oSIST prEN IEC 62271-211:2023
IEC CDV 62271-211 © IEC 2023 11 17C/901/CDV
340 5.7 Rated peak withstand current (I ) and rated dynamic current (I )
p d
341 For the rated peak withstand current of the GIS part of the direct connection 5.7 of IEC 62271-
342 1:2017 and for the rated dynamic current of the bushing 4.4 of IEC 60137:2017 are applicable.
343 It is recommended to assign the same value for the rated peak withstand current for the GIS
344 and the rated dynamic current for the bushing.
34
...