Study on the Analysis and Diagnosis of Dissolved Gases in Camellia Insulating Oil

Recently, as a kind of transformer oil with lots of outstanding characteristics such as high ignition point, reproducible, and natural degradation, vegetable insulating oil has becomes more and more popular in the oil-filled transformers. Thermal ageing as well as thermal and electrical faults, which can lead to the decomposition of insulating oil and insulating paper, will occur in operating transformers, then dissolved gases are formed and reach equilibrium in oil through diffusion process. In this paper, camellia oil as sample oil, thermal ageing as well as thermal and electrical faults simulation experiments of transformers were conducted, main characteristic gases decomposed by camellia insulating oil were obtained, and the changing rules of gas content with the changing of thermal ageing time, thermal fault temperature and discharge energy were also analyzed. Which indicated that if we increase the thermal ageing time, thermal faults temperature and discharge energy, the decomposition processes of camellia insulating oil could also be accelerated. And also the decomposition processes of camellia insulating oil and insulation paper under thermal and electrical stress were analyzed. Simulation results explained the gas production rules of thermal ageing and thermal faults as well as electrical faults of camellia insulating oil at microcosmic level. The result of above study provides theoretic support for condition assessment and operating maintenance of vegetable insulating oil-filled transformers, and also has great theoretical reference value and practical guiding significance for ensuring safe operation of vegetable insulating oil-filled transformers.