Abstract: Effects of different aromatics on electrical performance, anti-oxidation, solubility, gas tendency and thermal performance of transformer oil were studied. The results showed that in certain content range, aromatics has an negative effect on electrical performance of the oil with the order of heavy aromatics>medial aromatics > light aromatics, but has little influences on oxidation stability and thermal property, while medial and heavy aromatics are less susceptible to antioxidants; the solubility of base oil is mainly affected by aromatic hydrocarbon content, independent of the type of aromatics, the higher the content, the better solubility; aromatics, especially medial aromatics shows much better gassing tendency than light and heavy aromatics. Therefore, under the premise of good electrical performance and oxidation stability, the solubility and gassing tendency of transformer oil can be improved by addition of appropriate amount of aromatics.

Key words: aromatics, electrical performance, oxidation stability, solubility, transformer oil