In recent years, failures of water-blocking buffer layer in high voltage cables occur frequently, which has become a seriously threat to the security of the power transmission system. This paper summarized the latest research status of buffer layer failure, and put forward the possible preventive measures. Firstly, the accidents caused by the failure of water-blocking layer reported in recent years were enumerated, and the common characteristics of the failure were carefully analyzed. Then, on the basis of the introduction of structure and function of the water blocking buffer layer, combining with the literature and the experimental results of scanning electron microscope (SEM), energy disperse spectrometer (EDS), and X-ray diffraction (XRD), the phenomenon of white spot in buffer layer was explained, and it was proposed that the neutral water-blocking powder could effectively inhibit the generation of white spot. According to the research of buffer layer ablation, the ablation mechanism of buffer layer was divided into partial discharge ablation and current thermal effect ablation, and the problems of simulation modeling in the research were discussed. Finally, the existing researches on the ablation of the buffer layer was summarized and prospected, and it is suggested that reducing the gap between aluminum sheath and preventing the buffer layer from getting damp can effectively slow down the buffer layer ablation, but it needs further research to achieve.
| 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 |