Dissolved gas analysis associated with electrical degradation in MIDEL 7131 and mineral oil

With the increasing power consumption in over the world, the demand for power transformers has steadily risen, emphasizing the importance of transformer diagnostics. Among the various diagnostic methods, Dissolved Gas Analysis (DGA) is widely used due to its cost-effectiveness and efficiency. DGA identifies fault types by analyzing gases dissolved in the insulating oil when faults occur. Additionally, DGA can classify transformer faults into thermal and electrical faults based on the type and quantity of each gas. In this study, 30 times of AC Breakdown (BD) Tests were conducted for both the commonly used mineral oil and the eco-friendly MIDEL 7131 to examine their basic properties. During the AC BD Tests, DGA was performed to observe changes in gases generated as the electrical deterioration process occurred.