DefinePK

Abstract

Mineral oil has been used as a dielectric medium in a transformer. Nowadays, due to the environmental issue, the properties and characteristics of vegetable oils are investigated in order to check its suitability to be used in power transformers. However, vegetable oils have its limitations on costing, period of use and oxidation stability. Vegetable oils used are palm oil and coconut oil which are highly possible to oxidize rapidly. To reduce oxidation from happen, antioxidants tert-butyl-hydroquinone (TBHQ) and a-tocopherol are used. Samples were electrically and physically tested and comparisons were made with the mineral oil. Electrical test such as the breakdown voltage was conducted. Besides that, chemical properties such as dynamic viscosity and moisture content were also being investigated. Results from the laboratory studies have shown that each tested sample has their own advantages and disadvantages. TBHQ and a-tocopherol were found to reduce viscosity and moisture content, as well as increase the breakdown strength and aging resistance of oil.