Analisa Pengaruh Pembebanan dan Temperatur Lingkungan terhadap Umur Transformator 60 MVA Gardu Induk 150/70/20 kV

Abstract

The operational issue of the 60 MVA transformer at Maumere 150/70/20 kV Substation is the lack of information regarding the effects of transformer loading and ambient temperature on hot-spot temperature, insulation aging rate, loss of life, and estimated transformer life. This study aims to determine transformer loss of life, analyze the effects of loading and ambient temperature on hot-spot temperature and insulation aging rate, estimate transformer life, and evaluate insulating oil condition based on breakdown voltage test results. The study used transformer loading and ambient temperature data from January to March 2026, along with breakdown voltage test data from 2024 to 2026. The analysis included loading ratio, top-oil temperature, hot-spot temperature, relative aging rate, loss of life, and estimated transformer life. The results show that increasing loading and ambient temperature raises hot-spot temperature and accelerates insulation aging, resulting in greater loss of life and shorter transformer life. During the study period, the equivalent loss of life was 0.01120 pu, with an estimated transformer life of 20.49 years. At constant loading of 80%, 90%, and 100%, the hot-spot temperatures were 76.5°C, 85.7°C, and 96.1°C, with estimated lives of 19.64, 18.94, and 16.5 years, respectively. Ambient temperature increases from 23.1°C to 33.1°C raised the hot-spot temperature from 61.2°C to 71.2°C and increased the relative aging rate by approximately 3.18 times. These findings confirm that higher loading and ambient temperature accelerate insulation aging and reduce transformer life.