To address the dielectric matching problem in the oil-paper insulation system composed of cellulose insulating paper and low-permittivity insulating oil, this study employed low-temperature plasma for the surface treatment of insulating paper to improve the oil-paper insulation performance. A nanosecond pulse power supply was used to drive dielectric barrier discharge (DBD) to generate Ar/HMDSN plasma, and the effects of operating parameters such as precursor flow rate and treatment time on the properties of insulating paper and oil-paper insulation were investigated. The changes in surface physicochemical characteristics were analyzed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to explore the mechanism of property changes of the insulating paper. The results show that the insulation and mechanical properties of the insulating paper first increase and then decrease with the increase of precursor flow rate and treatment time, with the most significant improvement achieved after treated for 6 min under the flow rate of 15 mL/min. Compared with the untreated insulating paper, the relative permittivity of the insulating paper treated under these conditions decreases by 35.7%, the tensile strength increases by 23.1%, the flashover voltage and breakdown strength increase by 34.2% and 25.0%, respectively, and the flashover voltage and breakdown voltage of oil-paper insulation is correspondingly improved by 24.4% and 17.2%. During the plasma treatment process, low-polarity molecular fragments generated from the reaction precursor can penetrate the insulating paper and undergo deposition polymerization on the fiber surface, reducing molecular polarity, thereby comprehensively improving the both the surface and the bulk insulation properties of insulating paper.
| 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 |