高频电流局放和X光检测在高压电缆带电检测中的应用

High-frequency Current Detection on Partial Discharge and X-ray Detection On-line Detection of XLPE High-voltage Cable

随着交联聚乙烯(Cross-linked Polyethylene,XLPE)高压电缆在城市地下电网中广泛投运,其安全运行对于电网稳定越来越重要,找到切实可行的方法来监测现场运行电缆的绝缘势在必行。高频电流法是一种非侵入式的检测方法,安全可靠,针对某110 k V高压电缆接头绝缘击穿事故,对同结构电缆头进行局部放电,发现疑似局放信号并确定了其局放源,验证了此方法的实用性;X光检测是一种可实时成像的新型检测技术,通过一起电缆主绝缘击穿事故的X光检测,表明了利用X射线数字成像技术,可实现电缆内部结构的可视化诊断,快速准确的评估电缆缺陷程度。电缆高温运行实例将两方法综合应用,进一步验证了其有效性,为XLPE高压电缆局放带电检测提供理论支持。

Applications of cross-linked polyethylene（ XLPE） high- voltage cables in urban underground power grid are increasingly widespread. It is imperative to find out practical and feasible ways to monitor the insulation of onsite operation cables. High-frequency（ HF） current detection is a non-invasive test method. Aiming to a case of insulation puncture happened in a T junction, cable joints are inspected by using partial discharge（PD） monitoring system and the PD source is determined, through which the practicability of HF current detection is verified. X-ray detection is a new detection technology with real-time imaging, through the analysis of X-ray inspection example, insulation defects can be detected and visually analyzed by using X-ray digital imaging technology, and main insulation damages can be assessed quickly and accurately. HF current detection and X-ray detection are applied synthetically in the example that cables operated under the condition of high temperature, which further proved the effectiveness of these two methods and offered theoretical support for PD online detection of XLPE high-voltage cables.