电缆局部放电抗干扰技术研究-电测与仪表.DOCVIP

超高压电缆局放在线监测局放信号 提取技术研究及应用 马振祺1，刘克发2，温定筠1，赵军 2，江峰1 （1.国网甘肃省电力公司电力科学研究院，兰州 730050; 2. 国网甘肃省电力公司，兰州 730046） 摘要：局部放电检测已成为电缆绝缘在线检测技术的重要内容之一，由于局部放电信号微弱，且易受现场噪声干扰，因此如何准确识别并提取局放信号成为在线监测系统研究的重点和难点。本文通过运用联合抗干扰技术对局放信号进行处理，有效消除干扰并保留原始信号的必要形状特征；采用多相态谱图聚类分析法，从多相态谱图中提取放电特性，为局放在线监测提供判断依据和有效分析手段。经某水电厂330kV电缆线路局部放电在线监测系统现场应用证明该技术具有较好的实用性和推广性。 关键词：局放信号；干扰；在线监测；多相态谱图聚类分析； 中图分类号: TM93 文献标识码：B 文章编号：1001-1390（2016）00-0000-00 Research and application of PD signal extraction in UHV cable PD online monitoring Ma Zhenqi1, Liu Kefa2, Wen Dingjun1, Zhao Jun2, Jiang Feng1 (1.State Grid Gansu Electric Power Research Institute, Lanzhou 730050, China. 2. State Grid Gansu Electric Power Company, Lanzhou 730046, China) Abstract: PD detection has become one of the important contents of on-line testing technology in cable insulation. Due to the PD signal is weak and vulnerable to spot noises, thus, how to correctly recognize and extract signal of PD become the research focus and difficulty of on-line monitoring system. This paper aims to provide a basis for judgment and effective analysis means of PD on-line monitoring by using multiple anti-jamming technology to process PD signal, which effectively eliminates the interference and retains necessary shape features of the original signal. This paper uses multiphase spectrum clustering analysis means to extract discharge characteristics from multiphase spectrum. It proves that the technology has good practicability and popularization according to the field application of 330kV cable PD on-line monitoring system of a certain hydropower plant. Keywords: PD signal, interference, on-line monitoring, multiphase spectrum clustering analysis 0 引 言 局部放电是交联聚乙烯（XLPE）电缆绝缘劣化的表征和主要原因，局部放电试验作为交联聚乙烯电缆绝缘状况评估的首选方法已在带电检测和在线监测方面大量应用。在实际应用中，由于局部放电（PD）信号自身非常微弱，且现场存在各种电磁干扰，不断变化的现场干扰信号幅值常常比PD信号大两到三个数量级，将PD信号完全淹没，导致PD信号信噪比极低。因此有效的抑制和识别干扰，并准确提取PD信号的抗干扰技术成为局部放电在线检测系统的关键，直接影响到在线检测的准确度和灵敏度，是目前局部放电在线监测研究的重点和难点[1-4]。本文以某水电厂330 kV电缆线路局部放电在线监测系统建设为背景，重点对电缆局部放电在线监测采取的局放信号