IEC 60076-21:2011

Power transformers - Part 21: Standard requirements, terminology, and test code for step-voltage regulators

IEC 60076-21:2011/IEEE Std C57.15:2009 - Description of design types, tables of 50 Hz and 60 Hz ratings, supplementary ratings, construction, and available accessories are provided. Methods for performing routine and design tests applicable to liquid-immersed single and three-phase step-voltage regulators are described. Winding resistance measurements, polarity tests, insulation power factor and resistance tests, ratio tests, no load loss and excitation current measurements, impedance and load loss measurements, dielectric tests, temperature tests, routine and design impulse tests, short-circuit tests, control tests, calculated data, and certified test data are covered.

General Information

• Status: Published
• Publication Date: 14-Dec-2011
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: TC 14 - Power transformers
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 07-Dec-2018

Relations

• Revised: IEC 60076-21:2018 - Power transformers - Part 21: Standard requirements, terminology, and test code for step-voltage regulators
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60076-21



Edition 1.0 2011-12


™

IEEE Std C57.15
INTERNATIONAL




STANDARD



Power transformers –
Part 21: Standard requirements, terminology, and test code for step-voltage
regulators




IEC 60076-21:2011(E) IEEE Std. C57.15-2009

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IEC 60076-21



Edition 1.0 2011-12



™
IEEE Std C57.15
INTERNATIONAL



STANDARD





Power transformers –
Part 21: Standard requirements, terminology, and test code for step-voltage
regulators



INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XD
ICS 29.180 ISBN 978-2-88912-848-8

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– i – IEC 60076-21:2011(E)
 IEEE Std C57.15-2009




Contents


1. Overview . 1

1.1 Scope . 1

1.2 Purpose . 1

1.3 Word usage . 1


2. Normative references . 2


3. Definitions . 3

4. Service conditions . 9
4.1 Usual service conditions . 9
4.2 Loading at other than rated conditions .10
4.3 Unusual service conditions .10
4.4 Frequency .12
5. Rating data .12
5.1 Cooling classes of voltage regulators .12
5.2 Ratings .13
5.3 Supplementary continuous-current ratings .17
5.4 Taps .18
5.5 Operating voltage limits .18
5.6 Voltage supply ratios .20
5.7 Insulation levels .20
5.8 Losses .21
5.9 Short-circuit requirements .22
5.10 Tests .23
6. Construction .24
6.1 Bushings .24
6.2 Terminal markings .25
6.3 Diagram of connections .26
6.4 Nameplates .26
6.5 Tank construction .27
6.6 Components and accessories .31
7. Other requirements .32
7.1 Other supplementary continuous-current ratings .32
7.2 Other components and accessories .32
8. Test code.33

8.1 Resistance measurements .34
8.2 Polarity test .36
8.3 Ratio tests .37
8.4 No-load losses and excitation current .40
8.5 Load losses and impedance voltage .45
8.6 Dielectric tests .51
8.7 Temperature-rise tests .64
8.8 Short-circuit tests .73
8.9 Calculated data .77
9. Control systems .81
Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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IEC 60076-21:2011(E) – ii –
IEEE Std C57.15-2009


9.1 General .81

9.2 Control device construction .81

9.3 Control system requirements .82

9.4 Tests .83


Annex A (informative) Unusual temperature and altitude conditions .87

Annex B (informative) Field dielectric tests.89

Annex C (informative) Bibliography.90


Annex D (informative) IEEE List of Participants .92





Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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– iii – IEC 60076-21:2011(E)
 IEEE Std C57.15-2009


INTERNATIONAL ELECTROTECHNICAL COMMISSION


____________




POWER TRANSFORMERS –



Part 21: Standard requirements, terminology,

and test code for step-voltage regulators



FOREWORD


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International Standard IEC 60076-21/IEEE Std C57.15 has been processed through IEC
technical committee 14: Power transformers.
The text of this standard is based on the following documents:
IEEE Std FDIS Report on voting
C57.15-2009 14/688/FDIS 14/697/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.
Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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IEC 60076-21:2011(E) – iv –
IEEE Std C57.15-2009


A list of all the parts in the IEC 60076 series, published under the general title Power
transformers 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.


Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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– v – IEC 60076-21:2011(E)
 IEEE Std C57.15-2009


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Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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IEC 60076-21:2011(E) – vi –
IEEE Std C57.15-2009















Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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– vii – IEC 60076-21:2011(E)
 IEEE Std C57.15-2009













IEEE Standard Requirements,


Terminology, and Test Code for
Step-Voltage Regulators
Sponsor
Transformers Committee
of the
IEEE Power & Energy Society
Approved 11 September 2009
IEEE-SA Standards Board



Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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IEC 60076-21:2011(E) – viii –
IEEE Std C57.15-2009


Abstract: Description of design types, tables of 50 Hz and 60 Hz ratings, supplementary ratings,

construction, and available accessories are provided. Methods for performing routine and design

tests applicable to liquid-immersed single and three-phase step-voltage regulators are described.

Winding resistance measurements, polarity tests, insulation power factor and resistance tests,

ratio tests, no load loss and excitation current measurements, impedance and load loss

measurements, dielectric tests, temperature tests, routine and design impulse tests, short-circuit

tests, control tests, calculated data, and certified test data are covered.
Keywords: control, design tests, position indicator, routine tests, series transformer, tap changer,

Type A, Type B, voltage regulator


•







National Electrical Safety Code and NESC are both registered trademarks and service marks of the Institute of Electrical
and Electronics Engineers, Inc.

Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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– ix – IEC 60076-21:2011(E)
 IEEE Std C57.15-2009




IEEE Introduction

This introduction is not part of IEEE Std C57.15-2009, IEEE Standard Requirements, Terminology, and Test Code for

Step-Voltage Regulators.


The Working Group has undertaken the task to update this standard to:


a) Reflect the latest revisions of referenced documents IEEE Std C57.12.00™ [B13] and

IEEE Std C57.12.90™ [B16], and eliminate references to these standards in this standard

1

IEEE Std C57.15-2009 and duplicate applicable text.

b) Adapt the new IEEE approved format to ensure compatibility with the latest ISO and IEC

standards.
c) Include references to applicable IEC standards and keep IEEE standard references to a minimum.
This assists in setting up document as a possible candidate for a dual logo (IEC/IEEE).
d) Update tables of preferred ratings; include 50 Hz ratings. Ratings of 2.4 kV (45 BIL), 46 kV
(250 BIL), and 69 kV (350 BIL) have been removed from the three-phase 60 Hz voltage regulator
rating Table 5 (Table 4 in 1999 edition) due to historical inactivity of requests from users for
ratings.
e) Add bushing terminal connectors for current ratings of 669 A to 2000 A.
f) Clarify Type A and Type B designs and their resulting voltage regulation per extreme tap positions.
g) Review short-circuit requirements for distribution and substation applications and revise where
applicable.
Notice to users
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1
The numbers in brackets correspond to those of the bibliography in Annex C.
Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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IEC 60076-21:2011(E) – x –
IEEE Std C57.15-2009




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Published by the IEC under licence from IEEE. © 2009 IEEE. All rights reserved.

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– 1 – IEC 60076-21:2011(E)
 IEEE Std C57.15-2009



















POWER TRANSFORMERS –



Part 21: Standard requirements,
terminology, and test code for step-
voltage regulators



1. Overview
1.1 Scope
This standard describes electrical and mechanical requirements of liquid-immersed, single- and three-
phase, step-voltage regulators, not exceeding a regulation of 3000 kVA (for three-phase units) or 1000 kVA
(for single-phase units). This standard does not apply to load tap-changing power transformers.
1.2 Purpose
This standard is intended as a basis for the establishment of performance, limited electrical and mechanical
interchangeability, and general requirements of equipment described. It also assists in the proper selection

of such equipment.
1.3 Word usage
When this standard is used on a mandatory basis, the word shall indicates mandato
...