COMPARATIVE STUDY OF MINERAL OIL, SYNTHETIC ESTER, AND NATURAL ESTER AS LIQUID INSULATION IN TRANSFORMERS

• Main Author: Latif Jayyid, Unzhil
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86863
• Institution: Institut Teknologi Bandung

Power transformers are critical components in electrical power systems, performing the role of voltage converters in power distribution. The transformer's insulation system, consisting of insulating oil and paper, plays an important role in maintaining performance and preventing service interruptions. However, the aging process caused by thermal, chemical and electrical factors can lead to degradation of the insulation system, increasing the risk of transformer failure. This study aims to evaluate the performance of three types of transformer oil - mineral, synthetic ester and natural ester - under thermal aging conditions. Tests were conducted at temperatures of 100°C, 125°C and 150°C for 168, 504 and 840 hours to measure changes in physical, chemical and dielectric properties such as colour scale, moisture content, acidity, breakdown voltage, relative permittivity, resistivity, dielectric loss (tan ?), tensile strength and degree of polymerization of insulating paper. The results indicate that natural ester oil, particularly canola oil, has superior performance compared to mineral and synthetic ester oils. Natural ester oil shows better stability in breakdown voltage, resistivity and a slower decline in acidity and tan ? during aging. Synthetic ester oil also showed good results, although lower than natural ester, while mineral oil showed significant declines in all test parameters. At higher temperatures, natural ester oil showed faster degradation in paper insulation than synthetic ester. This research provides new insights into the potential of natural ester oil as an environmentally friendly and efficient alternative to mineral oil for transformer applications. Its thermal and dielectric stability provides better protection against aging and insulation degradation. However, challenges such as high cost, higher water content and the need for further research into long-term degradation mechanisms remain to be addressed. This study contributes to the development of more sustainable and environmentally friendly insulation materials.