文档介绍：华北电力大学(保定)
硕士学位论文
交联聚乙烯电缆局部放电信号检测与模式识别的研究
姓名:宋颖
申请学位级别:硕士
专业:电气工程电机与电器
指导教师:李永刚
2011-03
摘要
摘要
随着交联聚乙烯电缆在电网中的广泛应用,其绝缘状态越来越被人们所重
视。局部放电在线检测能够有效地实现对交联聚乙烯电缆的状态检修,而状态
检修是设备检修的发展方向。本文围绕交联聚乙烯电缆的局部放电信号,在局
部放电在线检测、抗干扰、模式识别等方面进行了研究。
通过试验研究完成对宽频带电流传感器的设计,并设计信号调理电路实现
对传感器输出信号的放大和滤波,进而通过采集卡和工控机实现对局部放电信
号的采集、显示、分析及保存。此外,还对交联聚乙烯电缆局部放电类型进行
分析,制作四种放电模型对其进行模拟试验。
由于局部放电信号比较微弱,而现场又存在大量干扰,所以运用抗干扰
技术对现场采集数据进行局部放电信号的提取至关重要。白噪声和周期干扰
是局部放电在线检测中的两类主要干扰,采用 CL 多小波消噪法对其进行消
噪研究。采用多小波矢量阈值法和相邻系数法对叠加随机白噪声的仿真局部
放电信号进行处理,验证多小波消噪法的有效性和相邻系数法的优越性;运
用多小波相邻系数法对周期性干扰和试验局部放电信号进行消噪。此外,还
对消噪后的局部放电模拟试验数据进行谱图显示和特征量的提取。
针对四种缺陷模型,选用合适的分类算法并以支持向量机作为模式识别
分类器,对其进行识别判断。通过对模式识别结果的分析研究,确定本系统
分类算法节点选择的最优顺序,并达到较好的识别效果。

关键词:交联聚乙烯电缆;局部放电;多小波;模式识别;支持向量机

I
Abstract
Abstract
With the wide application of XLPE cable in power system, more and more
attentions have been paid to its insulating state. Partial discharge detection can
effectively achieve the status maintenance of XLPE cable, so it’s the direction of
development of equipment maintenance. This paper focuses on the partial discharge
signal of XLPE cable, and researches on on-line partial discharge detection,
anti-interference, pattern recognition and other aspects.
In this paper, the design of wideband current sensor pleted by
experiments, and signal conditioning circuit is used to achieve the amplification and
filtering of sensor output signal. And then, use acquisition card and IPC to achieve
the acquisition, display, analysis and preservation of partial discharge signal. In
addition, this paper analysis the type of partial discharge of XLPE cable, and
produced four simulation models to partial discharge test.
Because partial discharge signal is weak and there is a lot of interference
on-site, it is critical to extract partial discharge signals from the on-site collected
data by the use of anti-interference technology. White noise and periodic
interference are two main types of int