高压XLPE绝缘电力电缆护层烧蚀机理分析

Ablation Mechanism Analysis on Metal Sheath of High Voltage XLPE Insulated Power Cable

文中针对某110 kV电缆护层烧蚀故障案例进行了分析,在综合考虑烧蚀点形貌、电缆结构及其运行环境后,提出了缓冲层与皱纹铝护套之间存在不良接触、金属护层上存在感应电压是造成电缆护层烧蚀的主要原因。在此基础上,建立了110 kV电缆电场仿真模型,设计了皱纹铝护套模型试样并开展了烧蚀模拟实验,分别验证了上述两种原因的合理性。为探究皱纹铝护层起始放电条件,明确放电规律,对模型试样在不同间隙下的起始放电电压进行了测试,测试结果进一步论证了上述烧蚀机理。文中工作能够为电缆设计及电缆故障分析提供有效指导。

In this paper,a case of 110 kV cable fault is analyzed.After investigating ablation morphology,cable structure and its operating environment,the causes of ablation,such as the bad connect between buffer layer and corrugated aluminum(Al)sheath as well as the inductive voltage on metal sheath,are put forward.To verify the reasonableness of the above two causes,a simulation model of 110 kV cable is established,a model sample of corrugated A1 sheath is designed and an ablation simulation experiment is carried out.For further exploring the A1 sheath discharge condition and law,the initial discharge voltage of the model sample under different gaps is tested,which further demonstrates the above ablation mechanism.The research results of this paper can provide an effective guide for cable design and fault analysis.