The traditional insulation reliability evaluation method based on failure life data for solid dielectric need long test time, and the failure data is little and difficult to obtain. In view of this issue, a reliability assessment method based on the test data of accelerated performance degradation was studied in this paper. Firstly, the average charge density was used as the characteristic parameter of performance degradation, and accelerated performance degradation tests were conducted to obtain performance degradation data under 140 kV/mm, 160 kV/mm, and 180 kV/mm of field strength, respectively. Secondly, the pseudo-failure life of XLPE insulation material under different field strengths was calculated, and its statistical distribution was determined. Finally, the pseudo-failure life data was expanded in combination with the virtual augmentation theory, and the expanded data was analyzed by statistical analysis methods. The results show that the performance reliability indicators such as sample reliability, failure distribution density function, and average life can be obtained through using accelerated performance degradation test method to assess the reliability of XLPE insulation. In combination with the accelerated life model theory, the life expectancy of the XLPE insulating material is 15.3 years under 20 kV/mm of stable field strength, and the reliability when reaching the expected life is 0.445 1.
| 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 |