10 kV电缆中间接头受潮XLPE-SiR绝缘界面放电演化分析

Moisture-induced Discharge Evolution Analysis of XLPE-SiR Insulation Interface in 10 kV Cable Joints

10 kV电缆中间接头交联聚乙烯硅橡胶(XLPE-SiR)绝缘界面在受潮条件下的放电行为严重影响配电网的可靠性,鉴于对绝缘界面放电行为的发展和特征研究较少,分析在受潮条件下10 kV电缆中间接头XLPE-SiR绝缘界面的放电行为,从仿真和试验2个方面验证XLPE-SiR绝缘界面的击穿过程。结果表明:在水分的作用下,XLPE-SiR绝缘界面会出现局部放电,并逐步演变为电弧放电。放电会产生2个影响:一方面引起绝缘材料的热解,形成电痕;另一方面,放电产生的热量导致水蒸发,有效地阻止了绝缘界面处放电的继续。随后,在存在电痕的情况下,进一步研究XLPE-SiR绝缘界面的放电行为。结果表明,当XLPE-SiR绝缘界面存在电痕时,水分的存在会迅速导致绝缘界面击穿。10 kV电缆中间接头绝缘界面受潮直接决定了其绝缘界面放电—短路故障的发展过程,因此在实际电缆中间接头的生产及施工工艺中需要加强防水管控。

The discharge behavior of the XLPE-SiR insulation interface in 10 kV cable joints under moist conditions significantly impacts the reliability of the distribution networks.However,research on the development and characteristics of insulation interface discharge behavior is scarce.Therefore,this study investigates the discharge behavior of the XLPESiR insulation interface in 10 kV cable joints under moist conditions and validates the breakdown process of the XLPE-SiR insulation interface through simulation and experiments.The results indicate that under the influence of moisture,the XLPE-SiR insulation interface exhibits partial discharge,evolving gradually into arc discharge.Discharge has two main effects,one is causing thermal decomposition of the insulation material,forming electrical tracks,and the heat generated by discharge leads to water evaporation,effectively preventing further discharge at the insulation interface.Subsequently,with the presence of electrical tracks,the paper further studies the discharge behavior of the XLPE-SiR insulation interface.The findings demonstrate that when electrical tracks are present on the XLPE-SiR insulation interface,the presence of moisture rapidly leads to breakdown of the insulation interface.The moisture content directly determines the development process of insulation interface discharge-short circuit faults in 10 kV cable joints,emphasizing the need to strengthen waterproof management in the production and construction processes of actual cable joints.