Effect of Moisture on the Electrical Treeing Characteristics in EP and ERIP
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更新:2022-08-29 16:12:27 浏览:185次
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摘要
Due to their excellent dielectric properties, mechanical properties, chemical corrosion resistance and other physical and chemical properties, Epoxy resin (EP) and epoxy resin impregnated paper (ERIP) are commonly used insulation materials, playing important roles in the field of power equipment and electrical equipment. The insulation of dielectric ensures the reliable operation of power equipment. However, moisture has a significant impact on EP and ERIP insulation performance, dielectric loss and other properties. In serious cases, it will lead to accelerated degradation of insulation and reduce the life of the equipment. The addition of crepe paper, with hydrophilic substances such as cellulose and ionic compounds , enhanced water absorption of the insulation material, and the effect of moisture on the insulation cannot be ignored. To research the effect of moisture on the electrical treeing characteristics in EP and ERIP, the experimental platform of electrical treeing at AC voltage and constant temperature was established. The needle electrodes were cast into the samples and maintain the gap distance of 2 mm. Electrical treeing experiments were conducted on moist and non-moist EP, ERIP samples at 16 kV AC voltage at 60 ℃ respectively. The results show moisture has little effect on the initiation of electrical trees. For the EP samples, the moisture results that the breakdown time of samples reduces from hours to minutes. For the ERIP samples, the moisture prompted the morphology of the electrical trees changing from branch like to bush like,which rarely occurring in the ERIP samples. The density of the trees increases and the fractal dimension increases significantly. The samples do not breakdown for more than 10 h. Tree length tends to saturate, but density keeps increasing. This may be due to the increased defects in the crepe paper when it is exposed to moisture and more optional growth paths for electrical tree branches. The branches shield each other and act as a voltage equalizer, resulting in a weakening of the local field strength. The results of this paper may help to explore the life of insulating materials and may provide a reference for the optimal design of insulation materials.
关键词
Moisture,epoxy,erip,insulation materials,Electrical trees
稿件作者
Gaoyi Shang
Xi’an Jiaotong University
Xuandong Liu
Xi'An Jiaotong University
Ming Chen
Xi'An Jiaotong University
Yuhang Shao
Xi'An Jiaotong University
Yingman Sun
Xi'An Jiaotong University
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