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

IEC 62271-211:2014 is applicable to single and three phase direct connections between gas-insulated metal-enclosed switchgear (GIS) for rated voltages above 52 kV and transformer arrangements to establish electrical and mechanical interchange ability and to determine the limits of supply of for the transformer connection. This first edition cancels and replaces the first edition of IEC TR 61639:1996 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) transfer from technical report to international standard;
b) the minimum voltage rating was changed from 72,5 kV to above 52 kV;
c) update of normative references;
d) definition of insulated junction including limit of supply;
e) definition of dielectric test of gas-insulated metal-enclosed switchgear for transformer connection in a three phase enclosure;
f) addition of interface tolerances at transformer side;
g) addition of transformer tolerances in service;
h) addition of exceptional loads for bushings and flanges;
i) consideration of oil- and gas-insulated transformers;
j) inclusion of three-phase enclosed direct connections. The contents of the corrigendum 1 of August 2015 and corrigendum 2 of August 2017 have been included in this copy.

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

L'IEC 62271-211:2014 est applicable aux raccordements directs monophasés et triphasés entre l'appareillage sous enveloppe métallique à isolation gazeuse (GIS) pour des tensions assignées supérieures à 52 kV et des dispositions de transformateurs pour établir des possibilités d'échanges électriques et mécaniques et pour déterminer les limites d'alimentation pour le raccordement du transformateur. Cette première édition annule et remplace la première édition de l'IEC TR 61639:1996. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) passage de l'état de rapport technique à l'état de norme internationale;
b) la caractéristique assignée de tension minimale passe de 72,5 kV à au-dessus de 52 kV;
c) mise à jour des références normatives;
d) définition de la jonction isolée incluant la limite d'alimentation;
e) définition de l'essai diélectrique de l'appareillage sous enveloppe métallique à isolation gazeuse pour le raccordement du transformateur dans une enveloppe triphasée;
f) ajout des tolérances d'interface du côté du transformateur;
g) ajout des tolérances du transformateur en service;
h) ajout de charges exceptionnelles pour les traversées et les brides;
i) prise en considération des transformateurs à isolation à huile et gazeuse;
j) inclusion des raccordements directs triphasés sous enveloppe. Le contenu du corrigendum 1 d'août 2015 et le corrigendum 2 d'août 2017 a été pris en considération dans cet exemplaire.

General Information

Status
Published
Publication Date
23-Apr-2014
Technical Committee
Current Stage
PPUB - Publication issued
Start Date
24-Apr-2014
Completion Date
24-Apr-2014
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IEC 62271-211
Edition 1.0 2014-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 211: Direct connection between power transformers and gas-insulated
metal-enclosed switchgear for rated voltages above 52 kV
Appareillage à haute tension –
Partie 211: Raccordements directs entre transformateurs de puissance et
appareillage sous enveloppe métallique à isolation gazeuse de tensions
assignées supérieures à 52 kV
IEC 62271-211:2014-04(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 62271-211
Edition 1.0 2014-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 211: Direct connection between power transformers and gas-insulated
metal-enclosed switchgear for rated voltages above 52 kV
Appareillage à haute tension –
Partie 211: Raccordements directs entre transformateurs de puissance et
appareillage sous enveloppe métallique à isolation gazeuse de tensions
assignées supérieures à 52 kV
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX S
ICS 29.130.10 ISBN 978-2-8322-1534-0

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 62271-211:2014 © IEC 2014
CONTENTS

FOREWORD ........................................................................................................................... 4

1 General ........................................................................................................................... 6

1.1 Scope ................................................................................................................ 6

1.2 Normative references ......................................................................................... 6

2 Normal and special service conditions ............................................................................. 7

2.1 Normal service conditions .................................................................................. 7

2.2 Special service conditions .................................................................................. 7

3 Terms and definitions ...................................................................................................... 7

4 Rating.............................................................................................................................. 8

4.1 Rated voltage (U ) ............................................................................................. 8

4.2 Rated insulation level ......................................................................................... 8

4.3 Rated frequency (f ) ........................................................................................... 9

4.4 Rated continuous current (I ) and temperature rise ............................................ 9

4.5 Rated short-time withstand current (I ) and rated thermal short-time

current (I ) ....................................................................................................... 9

4.6 Rated peak withstand current (I ) and rated dynamic current (I ) ...................... 9

p d

4.7 Rated duration of short-circuit (t ) and rated duration (t ) ................................. 9

k th

4.8 Rated filling pressure p of gas for insulation .................................................... 9

5 Design and construction ................................................................................................ 10

5.1 Limits of supply ................................................................................................ 10

5.2 Pressure withstand requirements ..................................................................... 11

5.3 Gas and vacuum tightness ............................................................................... 11

5.4 Mechanical forces applied on the connection interface ..................................... 12

5.5 Mechanical forces applied on the bushing flange ............................................. 12

5.6 Horizontal and vertical displacement ................................................................ 13

5.7 Vibrations ........................................................................................................ 13

6 Type tests ..................................................................................................................... 14

6.1 General ............................................................................................................ 14

6.2 Dielectric tests ................................................................................................. 14

6.2.1 Dielectric tests of bushing ............................................................... 14

6.2.2 Dielectric tests of transformer connection in a single phase

enclosure ........................................................................................ 14

6.2.3 Dielectric tests of transformer connection in a three phase

enclosure ........................................................................................ 14

6.3 Cantilever load withstand tests......................................................................... 14

6.4 Gas tightness tests .......................................................................................... 15

7 Routine tests ................................................................................................................. 15

7.1 General ............................................................................................................ 15

7.2 External pressure test of the bushing ............................................................... 15

7.3 Tightness tests ................................................................................................ 15

8 Standard dimensions and tolerances ............................................................................. 15

8.1 Single-phase direct connection between oil-filled transformer and

switchgear ....................................................................................................... 15

8.2 Three-phase direct connection between oil-filled transformer and

switchgear ....................................................................................................... 15

8.3 Connection between gas-insulated transformer and switchgear ....................... 16

---------------------- Page: 4 ----------------------
IEC 62271-211:2014 © IEC 2014 – 3 –

8.4 Transformer tolerances .................................................................................... 16

8.5 Mounting of the transformer on its foundation .................................................. 16

9 Information to be given with enquiries, tenders and orders ............................................ 16

10 Transport, storage, erection, operation and maintenance .............................................. 16

Bibliography .......................................................................................................................... 21

Figure 1 – Typical direct connection between power transformer and gas-insulated

metal-enclosed switchgear .................................................................................................... 17

Figure 2 – Standard dimensions for typical direct connection between power

transformer and gas-insulated metal-enclosed switchgear .................................................... 18

Figure 3 – Transformer tolerances for a typical direct connection shown on the
example of a three-phase power transformer connected to a single-phase gas-

insulated metal-enclosed switchgear ..................................................................................... 19

Figure 4 – Transformer tolerances for a typical direct connection shown on the

example of a three-phase power transformer connected to a three-phase gas-insulated

metal-enclosed switchgear up to 170 kV ............................................................................... 20

Table 1 – Moment and forces applied on the bushing flange and transformer ....................... 13

---------------------- Page: 5 ----------------------
– 4 – IEC 62271-211:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 211: Direct connection between power transformers and gas-
insulated metal-enclosed switchgear for rated voltages above 52 kV
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

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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

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

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Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

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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 62271-211 has been prepared by subcommittee 17C: High-voltage

switchgear and controlgear assemblies, of IEC technical committee 17: Switchgear and

controlgear.

This first edition cancels and replaces the first edition of IEC/TR 61639:1996 and constitutes

a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
a) transfer from technical report to international standard;
b) the minimum voltage rating was changed from 72,5 kV to above 52 kV;
c) update of normative references;
d) definition of insulated junction including limit of supply;
---------------------- Page: 6 ----------------------
IEC 62271-211:2014 © IEC 2014 – 5 –

e) definition of dielectric test of gas-insulated metal-enclosed switchgear for transformer

connection in a three phase enclosure;
f) addition of interface tolerances at transformer side;
g) addition of transformer tolerances in service;
h) addition of exceptional loads for bushings and flanges;
i) consideration of oil- and gas-insulated transformers;
j) inclusion of three-phase enclosed direct connections.
The text of this standard is based on the following documents:
FDIS Report on voting
17C/596/FDIS 17C/600/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.

A list of all parts in the IEC 62271 series, published under the general title High-voltage

switchgear and controlgear, 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 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.

The contents of the corrigendum 1 of August 2015 and corrigendum 2 of August 2017 have

been included in this copy.
---------------------- Page: 7 ----------------------
– 6 – IEC 62271-211:2014 © IEC 2014
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 211: Direct connection between power transformers and gas-
insulated metal-enclosed switchgear for rated voltages above 52 kV
1 General
1.1 Scope

This part of IEC 62271 is applicable to single and three phase direct connections between

gas-insulated metal-enclosed switchgear (GIS) for rated voltages above 52 kV and

transformer arrangements to establish electrical and mechanical interchange ability and to

determine the limits of supply of for the transformer connection.

Direct connections are immersed on one end in the transformer oil or insulating gas and on

the other end in the insulating gas of the switchgear.

Transformer arrangements are single-phase transformers with single-phase enclosed

arrangement, three-phase transformers with three single-phase enclosed arrangements or

three-phase transformers with a three-phase enclosed arrangement with three transformer

bushings.

The connection satisfies the requirements of IEC 62271-203 for gas-insulated metal-enclosed

switchgear, IEC 60076 for power transformer and IEC 60137 for completely immersed

bushings.

For the purpose of this international standard the term "switchgear" is used for "gas-insulated

metal-enclosed switchgear".
1.2 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 60076 (all parts), Power transformers
IEC 60137:2008, Insulated bushings for alternating voltages above 1 000 V
IEC 61936-1, Power installations exceeding 1 kV a.c. – Part 1: Common rules

IEC 62271-1:2007, High-voltage switchgear and controlgear – Part 1: Common specifications

IEC 62271-203:2011, High-voltage switchgear and controlgear – Part 203: Gas-insulated

metal-enclosed switchgear for rated voltages above 52 kV

IEC 62271-207, High-voltage switchgear and controlgear – Part 207: Seismic qualification for

gas-insulated switchgear assemblies for rated voltages above 52 kV
---------------------- Page: 8 ----------------------
IEC 62271-211:2014 © IEC 2014 – 7 –
2 Normal and special service conditions
2.1 Normal service conditions
Subclauses 2.1 of IEC 62271-1:2007 and IEC 62271-203:2011 are applicable.
2.2 Special service conditions
Subclauses 2.2 of IEC 62271-1:2007 and IEC 62271-203:2011 are applicable.
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 62271-1, as well as

the following apply.
3.1
bushing

device that enables a conductor to pass through a transformer tank, and insulates the

conductor from it

Note 1 to entry: The means of attachment (flange or fixing device) to the tank forms part of the bushing.

[SOURCE: IEC 60050-471:2007, 471-02-01, modified – update of the definition]
3.2
completely immersed bushing

a bushing both ends of which are intended to be immersed in an insulating medium other than

ambient air (e.g. oil or gas)
[SOURCE: IEC 60050-471:2007, 471-02-04]
3.3
gas-insulated switchgear enclosure

part of gas-insulated metal-enclosed switchgear retaining the insulating gas under the

prescribed conditions necessary to maintain safely the highest insulation level, protecting the

equipment against external influences and providing a high degree of protection to personnel

[SOURCE: 3.103 of IEC 62271-203:2011]
3.4
main circuit end terminal

part of the main circuit of a gas-insulated metal enclosed switchgear forming part of the

connection interface
[SOURCE: 3.2 of IEC 62271-209:2007]
3.5
transformer connection enclosure

part of the gas-insulated metal-enclosed switchgear which houses one end of a completely

immersed bushing fitted on a power transformer and a main circuit end terminal
3.6
maximum operating gas pressure

maximum pressure of the gaseous insulating medium in which one end of the bushing is

immersed, when in operation, the switchgear-power transformer connection assembly carrying

its rated normal current at the maximum ambient air temperature
---------------------- Page: 9 ----------------------
– 8 – IEC 62271-211:2014 © IEC 2014
3.7
design pressure of the enclosure
relative pressure used to determine the design of the enclosure

Note 1 to entry: It is at least equal to the maximum operating gas pressure in the enclosure at the highest

temperature that the gas used for insulation can reach under specified maximum service conditions

[SOURCE: 3.113 of IEC 62271-203:2011, modified – update of the note to entry]
3.8
rated filling pressure p of gas for insulation

pressure (in Pa), for insulation, referred to the standard atmospheric air conditions of +20 °C

and 101,3 kPa, which may be expressed in relative or absolute terms, to which the assembly

is filled before being put into service

[SOURCE: 3.6.5.1 of IEC 62271-1:2007, modified – update of the term and the definition]

3.9
minimum functional pressure p for insulation

pressure (in Pa), for insulation, referred to the standard atmospheric air conditions of +20 °C

and 101,3 kPa, which may be expressed in relative or absolute terms at which and above

which the characteristics of the switchgear-power-transformer connection are maintained and

at which replenishment becomes necessary

[SOURCE: 3.6.5.5 of IEC 62271-1:2007, modified – update of the term and the definition]

3.10
insulated junction

all parts which are needed to insulate the transformer from the switchgear including but not

limited to the insulating flange
3.11
proctor density

moisture-density relationship of a soil for a given compactive effort depending on the amount

of water the soil contains during soil compaction of controlled magnitude
4 Rating
4.1 Rated voltage (U )

The rated voltage shall be the rated voltage of the switchgear, selected from the following

standard values:

72,5 kV – 100 kV – 123 kV – 145 kV – 170 kV – 245 kV – 300 kV – 362 kV – 420 kV – 550 kV

NOTE Values 800 kV and higher are not considered because there is little experience at this time.

4.2 Rated insulation level

The rated insulation level for the GIS part in the transformer connection enclosure shall be

selected from the values given in the product standard IEC 62271-203. The rated insulation

level for the transformer bushing shall be selected from the values given in the product

standard IEC 60137.

NOTE Transformers can be tested at other insulation level values, according to the relevant standard.

The rated insulation level for a direct connection has to fulfil at least the requirements of

IEC 62271-203.
---------------------- Page: 10 ----------------------
IEC 62271-211:2014 © IEC 2014 – 9 –
4.3 Rated frequency (f )
Subclause 4.3 of IEC 62271-1:2007 applies.
4.4 Rated continuous current (I ) and temperature rise

The dimensions of the connection interfaces shown in Figure 2 allow a maximum value of

3 150 A for the rated continuous current. The connection interface is shown in Figure 1 as

parts 3 and 4.

The contact surfaces of the connection interface shall be silver-coated, copper-coated or bare

copper.

For the rated continuous current, the connection between switchgear and power transformer

shall be designed that the temperature of the transformer connection enclosure and the

temperature of the connection interface do not exceed the values given in 4.4.2 of

IEC 62271-203:2011.

4.5 Rated short-time withstand current (I ) and rated thermal short-time current (I )

For the rated short-time withstand current of the GIS part of the transformer connection 4.5 of

IEC 62271-1:2007 is applicable and for the rated thermal short-time current of the bushing 4.3

of IEC 60137:2008.
It is recommended to apply the same short-time currents for GIS and bushing.
4.6 Rated peak withstand current (I ) and rated dynamic current (I )
p d

For the rated peak withstand current of the GIS part of the transformer connection 4.6 of

IEC 62271-1:2007 is applicable and for the rated dynamic current of the bushing 4.4 of

IEC 60137:2008.

It is recommended to apply the same value for the rated peak withstand current for the GIS

and the rated dynamic current for the bushing.
4.7 Rated duration of short-circuit (t ) and rated duration (t )
k th

For the rated duration of the short-circuit current of the GIS part of the transformer connection

4.7 of IEC 62271-1:2007 is applicable and for the rated duration of the bushing 4.3 of

IEC 60137:2008.

It is recommended to apply the same value for the rated duration of short circuit for the GIS

and the rated duration for the bushing.
4.8 Rated filling pressure p of gas for insulation

The rated filling pressure p (or density) of gas for insulating is assigned by the switchgear

manufacturer.

If SF is used as the insulating gas, the minimum functional pressure for insulation p , used

to determine the design of the transformer bushing insulation, shall be not more than

0,35 MPa (absolute) at 20 °C.

For higher rated lightning impulse withstand voltage (BIL) the minimum functional pressure

may be increased.
---------------------- Page: 11 ----------------------
– 10 – IEC 62271-211:2014 © IEC 2014

If a gas different from SF or a gas mixture is used, the minimum functional pressure shall be

chosen to provide the same dielectric strength. The minimum functional pressure shall be

below the maximum operating pressure and design pressure of the enclosure.
5 Design and construction
5.1 Limits of supply
A typical direct connection is shown in Figure 1.

The limits of supply of the switchgear manufacturer and transformer manufacturer shall be

according to Figure 1.

To minimize circulating currents between the switchgear and the transformer, bonding

connections according to IEC 61936-1 shall be provided by the switchgear manufacturer

between the different single phase switchgear enclosures; capab
...

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