高压电缆户外终端绝缘老化特性观测及表征

Observation and characterization of insulation aging characteristics of outdoor terminals of high-voltage cables

为提升高压电缆户外终端应用的安全性,研究高压电缆户外终端全生命周期绝缘老化特性表征。选取使用年限有所差异的高压电缆户外终端样本,从外观特性、憎水特性、红外光谱特性、介电特性与表面电位衰减特性等方面表征样本全生命周期的绝缘老化特性。结果表明,随着高压电缆户外终端样本使用年限的提升,样本的外观裂纹明显加剧、憎水性逐渐下降、电子显微扫描中材料内部空洞量逐渐提升、介电常数逐渐提升、表面电位下降速度与幅度逐渐减缓,但介质损耗差异并不明显,随着运行年限的增加,高压电缆户外终端绝缘老化问题逐渐严重。

In order to improve the safety of the outdoor terminal application of high-voltage cables,the characteriza⁃tion of the insulation aging characteristics of the whole life cycle of outdoor terminals of high-voltage cables was studied.Samples of outdoor terminals of high-voltage cables with different service years were selected to character⁃ize the insulation aging characteristics of the samples in the whole life cycle from the aspects of appearance charac⁃teristics,hydrophobic characteristics,infrared spectroscopic characteristics,dielectric properties and surface poten⁃tial attenuation characteristics.The results showed that with the increase of the service life of the outdoor terminal sample of high-voltage cable,the appearance crack of the sample was significantly increased,the hydrophobicity was gradually decreased,the amount of voids in the material in the electron microscope scanning was gradually in⁃creased,the dielectric constant was gradually increased,and the decrease speed and amplitude of the surface poten⁃tial was gradually reduced,but the difference of the dielectric loss was not obvious.With the increase of the service life,the problem of insulation aging of outdoor terminal samples of high-voltage cables is gradually serious.