Analisis Tahanan Isolasi Trafo Daya Berdasarkan Pengujian Tegangan Tembus Minyak, Tangen Delta, Dan Rasio Pembebanan Di Gardu Induk 150 KV Batang

Isolation of the power transformer is a very important tool in the electricity transmission and distribution system. Therefore, the need for very strict supervision in the operation of the isolation. This needs to be done because the age factor of isolation really determines the good and bad functions of the transformer. Even poor condition of transformer isolation can cause operation failure and damage to the transformer. To find out the quality of the isolation, research is needed with a literature study to explore the material related to the research title and data collection at the substation. The data needed is the results of testing the polarization index, stress ratio, delta tangent, and testing for oil breakdown voltage. Based on the data that has been collected then proceed with calculations and analyzed to obtain better results. Ground-primary polarization index values indicate that they are still in good condition with a ground-primary value of 1.77 (good standards between 1.25 - 2.0). While testing the voltage ratio obtained an average value below 0.7% (good standard). Delta tangent testing also showed good conditions with a value of 0.204%. For oil testing, it can be obtained that the average condition is still good, namely oil below 8.6 kV and OLTC oil at 10.4%