XLPE电缆绝缘热老化特性规律实验研究

Experimental Study on Thermal Aging Characteristics of XLPE Cable Insulation

目前石化企业高压电缆“老龄化”日益严重、运行风险逐年增大,热老化是影响电缆整体绝缘状态的重要因素。开展XLPE电缆绝缘材料制备实验和模拟热老化实验,获取了0~480 h的XLPE薄片老化试样;并分别开展介质损耗因数、极化指数和局部放电测量实验,得到关键绝缘特征量随绝缘热老化程度的特性规律。研究结果表明,介质损耗因数、极化指数随XLPE电缆绝缘老化过程分别近似呈指数规律增长、均匀增长,局部放电量随老化过程逐渐增大且放电趋于集中。研究结果对于探明XLPE电缆绝缘劣化特性规律及验证XLPE绝缘材料热老化机理具有指导意义。

At present,the“aging”of high-voltage cables in petrochemical enterprises is becoming more and more serious,and the operation risk is increasing year by year.XLPE cable insulation material preparation experiment and simulated thermal aging experiment were carried out,and XLPE wafer aging samples were obtained for 0~480 h.The measurement experiments of dielectric loss factor,polarization index and partial discharge were carried out respectively,and the characteristic law of key insulation characteristics with insulation thermal aging degree was obtained.The results showed that the dielectric loss factor and polarization index increased exponentially and uniformly with the aging process of XLPE cable insulation,and the local discharge gradually increased with the aging process and the discharge tended to be concentrated.The research results were of guiding significance for exploring the characteristics of XLPE cable insulation deterioration and verifying the thermal aging mechanism of XLPE insulation materials.