Omicron CP TD1 - Influence of Parameters on DF

CP TD1 User Manual
34 OMICRON
Influence of different parameters as water content, temperature and aging on DF
Figure 4-5 shows the breakdown voltage and the DF in oil, dependent on the water content
[1]
. With low
water content, the breakdown voltage is very sensitive; with higher water content, the DF is a good
indicator.
Figure 4-5: Breakdown voltage and DF in oil, dependent on the water content
Figure 4-6 shows the DF of new and used oil, dependent on the temperature. With higher temperatures,
the viscosity of the oil decreases so the particles, ions and electrons can move easier and faster. Thus
the DF increases with temperature.
Figure 4-6: DF of new and aged oil, dependent on temperature
1. Krüger, M.: "Prüfung der dielektrischen Eigenschaften von Isolierflüssigkeiten", ÖZE, No. 5, Vienna, May 1986
600
500
400
300
200
100
0
60
50
40
30
20
10
0
0 20 40 60 80 100 120 140 160 180
200
kV/cm
Breakdown voltage
Dissipation factor
tan δ
ε
d
0
/
00
mg/kgWater content
-20-30 -10 0 10 20 30 40 50 60 70 80 90 100
4
3
2
1
10
1
10
2
10
3
10
4
1
°C
WDQį
%
Oil temperature
Dissipation Factor:
Dependency of the temperature
1 = new oil
2, 3 and 4 = used oil