In oil-immersed systems, the rapid development of discharge faults has the characteristic of high gas production and fast gas generation rates. As a result, the generated characteristic gases may not have enough time to dissolve in oil. The majority of these gases escape to the oil surface and enter the gas relay, leading to that a large amount of effective gas for transformer diagnosis and early warning is unable to reach dissolution equilibrium in time, which makes the commonly used dissolved gas analysis method in power industry unable to accurately diagnose faults. Based on this, an experimental platform for studying the gas production law on the oil surface under fast-developing discharge faults of oil-immersed insulation system was constructed. The characteristic gas information on the oil surface of the oil-immersed insulation system during fast-developing discharge faults was obtained. The results show that the concentration of characteristic gases in the liquid phase does not increase significantly in the short period after fault occurred, while there is a large amount of characteristic gases in the gas phase at this time. When there is high-energy discharge in the system, CO, CO2, CH4, and H2 will accumulate on the oil surface, and these four gases can be used as characterization basis for high-energy discharge faults. On this basis, C2H6, C2H4, and C2H2 will also accumulate on the oil surface when there is spark discharge, and these three gases can be used as diagnostic basis for spark discharge.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |