Omicron CP TD1 Reference Manual

CP TD1 Reference Manual V 1.44
158
12.9.8 Winding Resistance Measurement of a 100 MVA
Transformer
The 220 kV/110 kV – 100 MVA transformer under test manufactured in 1995
was found to have conspicuously high quantities of gas in the oil, from which the
conclusion was drawn of inner overheating. The measurement results taken with
the test system (Figure 12-16) show a very good match with the values
measured by the manufacturer for the mid-position (denoted as tap 10) of the
tap selector in all phases, where direct connection to the main winding occurs.
Figure 12-16 Winding resistance measurement H1-H0
In the measurements taken with the test system, the different winding
temperatures were considered and all other taps showed a significant increase
compared to the original measured values. The differences are more than 10%
or, in absolute values, up to 70 m. The deviations between switching upwards
and switching downwards are likewise clearly significant. This shows that the

Omicron CP TD1 Specifications

General

Brand	Omicron
Model	CP TD1
Category	Measuring Instruments
Language	English