高压XLPE电缆缓冲层烧蚀故障机理分析与结构优化

高压交联聚乙烯(cross-linked polyethylene,XLPE)电缆缓冲层烧蚀故障频发，在行业内引起广泛关注。电缆结构优化有利于解决放电烧蚀问题，文中从缓冲层放电灼伤机理角度出发，建立电缆有限元模型进行电场仿真，分析讨论不同结构参数下气隙电场分布的变化，并开展模拟试验对结构优化方案进行研究。结果表明：在满足电缆设计要求的前提下，减小缓冲层厚度、减小轧纹深度、增加金属套和缓冲层的挤压深度有利于减弱接触不良导致的气隙电场畸变；平滑铝套结构与缓冲层的接触电阻较小，在抑制缓冲层放电烧蚀故障方面具有优势。

Ablative fault mechanism analysis and structure improvement of buffer layer of high voltage XLPE cable

Ablation failures of buffer layer in high voltage cross-linked polyethylene (XLPE) cables occur frequently,which has attracted widespread attention in the industry. The optimization of cable structure is conducive to solving the problem of discharge ablation. From the perspective of the discharge burn mechanism of buffer layer,the finite element model of cable is established for electric field simulation to analyze and discuss the variation of air gap electric field distribution under different structural parameters,thus designing and studying the structure optimization scheme. The results show that,on the premise of satisfying the design requirements of cable,it is beneficial to reduce the air gap electric field distortion because of poor contact,by reducing the thickness of the buffer layer and corrugated depth,as well as increasing extrusion depth between the metal sheath and the buffer layer. The smooth aluminum sleeve structure has low contact resistance with the buffer layer,so it has advantages in restraining fault of buffer layer discharge ablation.