基于关联维数与小波包-AR谱的串联故障电弧特征研究  

Research on series fault arc characteristics based on correlation dimension and wavelet packet-AR spectra

作　　者：刘丽智 刘艳丽[1] 殷煜炜 陈昌垦 

机构地区：[1]辽宁工程技术大学电气与控制工程学院 [2]江苏省电力有限公司阜宁供电分公司 [3]国网十堰供电公司

出　　处：《电子测量与仪器学报》2018年第9期108-116,共9页Journal of Electronic Measurement and Instrumentation

基　　金：国家自然科学基金(51674136);辽宁省教育厅青年基金(LJ2017QL010)资助项目

摘　　要：供配电系统的电气连接点常因接触松动、机械振动等原因产生串联型故障电弧,串联型故障电弧易引起电气火灾等电气安全事故,影响供电的可靠性。为进一步研究串联故障电弧的特征,在实验室开展了接触松动和机械振动两种生弧条件下的串联故障电弧实验,提出了基于分形理论和小波包-自回归(AR)谱分析的串联型故障电弧特征提取方法。首先对实验电流信号进行分形特征分析,计算各种工作状态下电流信号的关联维数;然后对信号进行小波包分解及重构,对重构后的各频段信号进行AR谱分析,研究不同频段信号AR谱能量在燃弧前后的变化规律,构建以关联维数和E3,0频带能量比例系数为特征量的特征向量。分析结果表明,分形关联维数和小波包-AR谱能量能够有效的描述各类型负载在两种生弧方式下的串联型故障电弧,可用于诊断因接触松动及机械振动原因引起的串联故障电弧。Electrical connection points of power supply and distribution systems often produce series fault arcs due to contact looseness,mechanical vibration,etc. Series fault arcs can easily cause electrical safety accidents such as electrical fires and affect the reliability of power supply. In order to further study the characteristics of series fault arcs,a series of fault arcs experiments were carried out in laboratory under two kinds of arc generation conditions including contact loosening and mechanical vibration. A series fault arcs feature extraction method based on fractal theory and wavelet packet-auto regressive( AR) spectrum analysis was proposed. Firstly,the fractal characteristics of the experimental current signals were analyzed,and correlation dimensions of the current signals under various working conditions were calculated. Secondly,the signal was decomposed and reconstructed by wavelet packet,and AR spectrum analysis was performed on the reconstructed signal in each frequency band. The variation law of AR spectrum energy before and after arcing in different frequency bands was studied. Thirdly,a feature vector based on correlation dimensions and scale coefficients of the E3,0 frequency band wasconstructed. The analysis results showed that the fractal correlation dimension and wavelet packet-AR spectrum energy could effectively describe series fault arcs under different arcing modes for each type of load. It could be used to diagnose series fault arcs caused by contact looseness and mechanical vibration.

关 键 词：故障电弧 关联维数 小波包-AR谱能量 接触松动 机械振动 

分 类 号：TM501.2[电气工程—电器]