05-Short Circuit Dynamic Comparative Statement

8/17/2019 05-Short Circuit Dynamic Comparative Statement

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TECHNICAL REPORT CSQ

CSQ n° 9101.TESA

Certificazione sistema di Qualità

ISO9001

POWER TRANSFORMER pag. 1/15

Page 1 of 15

Ability to Withstand Dynamic Effects of Short Circuit

Comparative Statement

DATA: 28/03/10ISSUED BY APPROVED BY


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CSQ n° 9101.TESA


ISO9001


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Ability to Withstand Dynamic Effects of Short Circuit Comparative Statement

The IEC 60076-5 standard gives the comparison criteria to verify the applicability of a short-circuit withstand

test performed on a transforer to a similar transformer. The technical feature to be taken into consideration are

prescribed in the Annex B “Guidance for the identification of a similar transformer” and showed in Table 1

below.

Tesar has positively tested a Cast-Resin Transformer 2500 kVA at CESI Laboratory (test certificate n.

A7030507 dtd 3rd

Ddecember 2007):

This test certificate is applicable to the transformers having characteristics according to the content of Table 1

and Table 2

Table 1

Critical features as per IEC 60076.5 Tested Transformer 2500

kVA

Similar Transformers

same type of operation: distribution type distribution type

same conceptual design: cast resin, core type with

concentric and circularwindings

cast resin, core type with

concentric and circular windings

same arrangement of main windings and

geometrical sequence

HV : cast

LV: pre-preg

Geometrical sequence :

HV outside , LV inside

Same as the tested transformer

same type of winding conductors Al Same as the tested transformer

same type of main windings layer for LV and HV coils layer for LV and HV coils

absorbed power for at short circuit between

30% and 130% of that of the reference unit

from 12.038,52 up to

52166,93 p.u.

≤ 52.166,93 p.u.

axial forces and relative winding stresses at

short circuit not exceeding 110% of those in

the reference unit

as per design Transformers in Table 2 have

forces and stresses within the

limit required

same manufacturing process HV : cast

LV : pre-preg

Same

same clamping and supporting arrangement Correlated to the short

circuit current

Same arrangement , correlated to

the short circuit current

Table 2


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CSQ n° 9101.TESA


ISO9001


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Tested transformer

Rated Power [kVA] 2500

Impedance [%] 6,23

Absorbed power at S.C. [pu] 40.128,41

Range 30% [pu] 12.038,52

Range 130% [pu] 52.166,93

Similar transformer

Rated Power

Rated

Impeda

nce

Absorbed

power at

S.C.

Impedance

min

Impedance

max

[kVA] [%] [pu] [pu] [pu]

500 4 12.500,00 0,96 4,15

630 4 15.750,00 1,21 5,23

800 6 13.333,33 1,53 6,65

1000 6 16.666,67 1,92 8,31

1250 6 20.833,33 2,40 10,38

1500 6 25.000,00 2,88 12,46

1600 6 26.666,67 3,07 13,29

2000 6 33.333,33 3,83 16,61

2500 6 41.666,67 4,79 20,77

2700 6 45.000,00 5.17 22,43

3000 6 50.000,00 5,75 24,92


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05-Short Circuit Dynamic Comparative Statement