Certificazione sistema di Qualità
TECHNICAL REPORT
CSQ
ISO9001
CSQ n° 9101.TESA
POWER TRANSFORMER
pag. 1/15
Ability to Withstand Dynamic Effects of Short Circuit
Comparative Statement
DATA: 28/03/10
ISSUED BY
APPROVED BY
Page 1 of 15
Certificazione sistema di Qualità
TECHNICAL REPORT
CSQ
ISO9001
CSQ n° 9101.TESA
POWER TRANSFORMER
pag. 2/15
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
same type of operation:
same conceptual design:
same arrangement of main windings and
geometrical sequence
same type of winding conductors
same type of main windings
absorbed power for at short circuit between
30% and 130% of that of the reference unit
axial forces and relative winding stresses at
short circuit not exceeding 110% of those in
the reference unit
same manufacturing process
same clamping and supporting arrangement
Tested Transformer 2500
kVA
distribution type
cast resin, core type with
concentric and circular
windings
HV : cast
LV: pre-preg
Geometrical sequence :
HV outside , LV inside
Al
layer for LV and HV coils
from 12.038,52 up to
52166,93 p.u.
as per design
HV : cast
LV : pre-preg
Correlated to the short
circuit current
Similar Transformers
distribution type
cast resin, core type with
concentric and circular windings
Same as the tested transformer
Same as the tested transformer
layer for LV and HV coils
≤ 52.166,93 p.u.
Transformers in Table 2 have
forces and stresses within the
limit required
Same
Same arrangement , correlated to
the short circuit current
Table 2
2
Certificazione sistema di Qualità
TECHNICAL REPORT
CSQ
ISO9001
CSQ n° 9101.TESA
POWER TRANSFORMER
Tested transformer
Rated Power
Impedance
Absorbed power at S.C.
Range 30%
Range 130%
[kVA]
[%]
[pu]
[pu]
[pu]
2500
6,23
40.128,41
12.038,52
52.166,93
Rated
Impeda
nce
[%]
4
4
6
6
6
6
6
6
6
6
6
Absorbed
Impedance Impedance
power at
min
max
S.C.
[pu]
[pu]
[pu]
12.500,00
0,96
4,15
15.750,00
1,21
5,23
13.333,33
1,53
6,65
16.666,67
1,92
8,31
20.833,33
2,40
10,38
25.000,00
2,88
12,46
26.666,67
3,07
13,29
33.333,33
3,83
16,61
41.666,67
4,79
20,77
45.000,00
5.17
22,43
50.000,00
5,75
24,92
pag. 3/15
Similar transformer
Rated Power
[kVA]
500
630
800
1000
1250
1500
1600
2000
2500
2700
3000
3
4
5
6
7
8
9
10
11
12
13
14
15