1. Dielectric strength(kV)
Table 1. Standard Value Of Various Parameters Related To Power Transformer
Properties
U≤66kV
66<U≤22kV
U>220kV
Score
Dielectric strength(kV)
≥40
≥47
≥50
100
35-40
42-47
45-50 80
30-35
40-45 60
<30
<35
<40 40
Acidity (mg(KOH/g))
≤.05
≤0.04
≤0.03
≥0.2
≥0.15
≥0.1
IFT(25®C)
≥25
≥30
≥35
20-25
23-30
25-35
15-20
19-23
<15
<19
<20
Tan δ
<1.5
<1
<0.5
1.5-3
1-1.5
0.5-1
3-4
1-2 ≥4 ≥3 ≥2
Colour
Light yellow
Yellow
Dark yellow
Chocolate brown
Leakage current
100µA
Power factor
0.8
Sonali Mayuresh Akolkar et al. Remaining Life Assessment of Power Transformer. Journal of Automation and Control, 2014, Vol. 2, No. 2, doi: /automation-2-2-2
© The Author(s) Published by Science and Education Publishing.