The buffer layer defects of high-voltage crosslinked polyethylene (XLPE) cable occur frequently, which makes the detection method become the focus to be studied. Here, the broadband impedance detection technology for the buffer layer defects of high-voltage XLPE cables with corrugated aluminium sheath is investigated. There are nine cable samples, including new and defective ones. Some of the defective cables are artificial, and the other is retired cables. The influence of wiring mode, the circumferential relative position of electrodes, cable length, artificial white powder, artificial damp, and retired defective cables on the impedance spectrum is studied. It is found that the wiring mode of the insulation shield/aluminium sheath at the end of the cable can effectively detect the buffer layer defects. And the broadband impedance amplitude spectrum of the buffer layer in defective cable, measuring at various circumferential relative positions, is obviously different. When there are white powders, air gaps, or ablation in the buffer layer, the broadband impedance spectrum (BIS) will increase by several times. When the buffer layer is damped, the BIS will reduce. The research here provides theoretical support and technical methods for the buffer layer defects of XLPE cable with corrugated aluminium sheath.

中文翻译：

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110 kV波纹铝护套交联聚乙烯电缆缓冲层缺陷宽带阻抗谱检测

高压交联聚乙烯(XLPE)电缆缓冲层缺陷的频繁发生，使得其检测方法成为研究的重点。本文研究了波纹铝护套高压交联聚乙烯电缆缓冲层缺陷的宽带阻抗检测技术。有九个电缆样品，包括新的和有缺陷的。一些有缺陷的电缆是人造的，另一些是退役的电缆。研究了接线方式、电极周向相对位置、电缆长度、人工白粉、人工潮湿、退役缺陷电缆对阻抗谱的影响。发现电缆末端绝缘屏蔽/铝护套的接线方式可以有效检测缓冲层缺陷。并且在不同周向相对位置测量的有缺陷电缆的缓冲层的宽带阻抗幅值谱是明显不同的。当缓冲层中存在白色粉末、气隙或烧蚀时，宽带阻抗谱（BIS）会增加数倍。当缓冲层受阻尼时，BIS会降低。该研究为波纹铝护套交联聚乙烯电缆缓冲层缺陷的解决提供了理论支持和技术方法。