Investigating bubble formation in vegetable and mineral oil impregnated transformer paper insulation systems

Paper presents a review of past research on factors influencing bubble formation in transformer mineral oils. Previous research done by Monash University is also presented and compared to as the equipment and method will form the basis of future research using vegetable transformer oils. Results of past experiments show that bubble formation depends on: the moisture content of paper, the gas content of oil, the quality and age of the insulation material and rate of temperature rise. A brief description of future work and expectations are presented. The result will be used for additional considerations of the use of vegetable oil as a substitute for mineral oil.