Abstract:
In high voltage system, the insulation used in electrical equipment plays an important role,
especially the transformer oil which is commonly used. There may be breakdown or partial
discharge occurring during an operation. This causes the transformer oil to be heated, leading to the
deterioration of the insulation. This research represents an analysis of the life-accelerated
transformer oil. The test was carried out in four cases. Firstly, the transformer oil was accelerated
for deterioration using only heating. Secondly, the transformer oil was accelerated with 10
breakdowns and then heating until its temperature reached 60 C celsices every day. For the 31rd and last
cases, the processes were similar to those in the 2nd case but the number of breakdowns was changed
to 30 and 50 times a day, respectively. The values of breakdown voltage and dielectric dissipation
factor at various frequencies and temperatures were measured. The transformer oil in this research is
type I transformer oil according to ASTM D 3487-08. The results show that the dielectric
dissipation factor increases as the number of test day increases. Furthermore, the dissipation factor
of the 1st case is lower than that of other cases. However, the breakdown voltage of the 1st case is the
highest.