PENGARUH KEGAGALAN MINYAK TRANSFORMATOR DAYA 18.5 MVA PLTG UNIT 1 DI PT PLN (PERSERO) SEKTOR PEMBANGKITAN KERAMASAN

In the power transformer frequent disturbances that can cause failure of the transformer. It is necessary for the care and maintenance of power transformers, one with transformer oil testing is test DGA. The test is performed to determine whether there is an abnormality in the transformer. DGA testing a transformer condition analysis is performed based on the amount of gas dissolved in transformer oil. In this paper, using Roger's ratio for failure analysis of transformer failure. Roger's Ratio Method showed the occurrence of partial discharge and data TDCG shows the results of 5729 ppm indicating that the transformer is in a state of decomposition 4 which has a high level of oil. Calculation of the current rise in consecutive years 2014-2016 amounted to 171 kA, 174 kA and 195 kA and the calculation of the temperature are 154.76 ° C, 159.34 ° C and 201.6 ° C. The calculation of current and temperature rise by DGA testing indicates that the current rise in the transformer effect on temperature rise in transformer insulating oil