IEC/IEEE 60076-57-1202:2017

IEC/IEEE 60076-57-1202 ®
Edition 1.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Power transformers –
Part 57-1202: Liquid immersed phase-shifting transformers

Transformateurs de puissance –
Partie 57-1202: Transformateurs déphaseurs immergés dans un liquide

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IEC/IEEE 60076-57-1202 ®
Edition 1.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Power transformers –
Part 57-1202: Liquid immersed phase-shifting transformers

Transformateurs de puissance –

Partie 57-1202: Transformateurs déphaseurs immergés dans un liquide

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.180 ISBN 978-2-8322-4258-2

– 2 – IEC/IEEE 60076-57-1202:2017
© IEC/IEEE 2017
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
2.1 IEC references . 7
2.2 IEEE references . 7
3 Terms and definitions . 8
4 Use of normative references . 11
5 Service conditions . 11
5.1 General . 11
5.2 Usual service conditions . 11
5.2.1 Switching arrangement . 11
5.2.2 Power flow . 11
5.2.3 Operation with two or more PSTs in series or parallel . 11
5.2.4 Phase unbalance . 12
5.2.5 Surge protection . 12
6 Rating and general requirements . 12
6.1 Rated power . 12
6.2 Loading at other than rated conditions . 12
6.3 Specification of buck capability . 12
6.4 Cooling modes . 13
6.5 Short circuit impedance and load phase angle capability . 13
6.5.1 Specification . 13
6.5.2 Short circuit impedance for asymmetric designs . 13
6.6 Neutral earthing (grounding) . 13
6.7 Rated voltage . 13
6.8 Voltage variation and asymmetric design . 13
6.9 Rated frequency . 14
6.10 Operation at higher than rated voltage and/or at other than rated frequency . 14
6.11 Highest voltage for equipment and dielectric test levels . 14
6.12 Taps . 14
6.13 Sound level . 14
6.14 Transport . 14
7 Construction . 14
7.1 General . 14
7.2 Liquid-filled connections between tanks . 15
7.3 Liquid insulation and preservation system . 15
7.4 Alignment between tanks . 15
7.5 Core and core frame earthing arrangements . 16
7.6 Test connections . 16
8 Short circuit capability . 16
9 Connection phase displacement symbols . 16
9.1 General . 16
9.2 Special symbols for PSTs . 16
9.3 Clock number notation . 17
9.4 Examples . 17
9.4.1 Single core phase shifting transformers . 17

© IEC/IEEE 2017
9.4.2 Two core phase shifting transformers . 19
9.4.3 Transformers incorporating a phase shifting element . 21
10 Rating plates (nameplates) . 22
11 Terminal markings and phase rotation . 23
12 Information to be provided by the manufacturer . 23
13 Tests . 24
13.1 General . 24
13.2 Routine tests. 24
13.3 Type (design) tests . 24
13.4 Special tests . 24
13.5 Winding resistance. 25
13.6 Measurement of voltage ratio, phase angle and check of phase
displacement . 25
13.7 Measurement of short-circuit impedance and load loss . 25
13.8 Temperature-rise test . 26
13.9 Measurement of no-load loss and current . 26
13.10 Determination of sound level . 26
13.10.1 General . 26
13.10.2 For PSTs with one combined cooling system . 26
13.10.3 For PSTs with separate exciting and series unit cooling systems . 27
13.11 Measurement of zero sequence impedance . 27
13.12 Dielectric tests . 27
13.12.1 General . 27
13.12.2 Induced voltage test with partial discharge measurement (IVPD) . 28
13.12.3 Switching impulse test (SI) . 28
13.12.4 Lightning impulse test . 28
13.12.5 Lightning impulses applied to multiple line terminals simultaneously
(LIMT) . 29
13.13 Tests on on-load tap-changers – operation test . 29
13.14 Leak testing with pressure . 30
13.15 Vacuum deflection test . 30
13.16 Pressure deflection test . 30
14 Tolerances . 30
14.1 General . 30
14.2 Tolerance for impedance and phase angle . 30
Annex A (informative) Check list of information to be provided with enquiry and order . 32
A.1 Rating and general data . 32
A.1.1 Normal information . 32
A.1.2 Special information . 33
A.2 Parallel operation . 34
Annex B (informative) Behaviour of a phase shifting transform
...