The distribution network exhibits complex structural characteristics,which makes fault localization a challenging task.Especially when a branch of the multi-branch distribution network fails,the traditional multi-bran...The distribution network exhibits complex structural characteristics,which makes fault localization a challenging task.Especially when a branch of the multi-branch distribution network fails,the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network system.In this paper,the multi-branch mainline is decomposed into single branch lines,transforming the complex multi-branch fault location problem into a double-ended fault location problem.Based on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines,the endpoint reference time difference matrix S and the fault time difference matrix G were established.The time variation rule of the fault-traveling wave arriving at each endpoint before and after a fault was comprehensively utilized.To realize the fault segment location,the least square method was introduced.It was used to find the first-order fitting relation that satisfies the matching relationship between the corresponding row vector and the first-order function in the two matrices,to realize the fault segment location.Then,the time difference matrix is used to determine the traveling wave velocity,which,combined with the double-ended traveling wave location,enables accurate fault location.展开更多
针对传统电缆故障定位法受波速和噪声影响导致的波头识别不准确及故障定位精度差问题,提出一种基于小波降噪、经验小波变换(empirical wavelet transform,EWT)和Teager能量算子(Teager energy operator,TEO)的电缆故障定位方法。首先,...针对传统电缆故障定位法受波速和噪声影响导致的波头识别不准确及故障定位精度差问题,提出一种基于小波降噪、经验小波变换(empirical wavelet transform,EWT)和Teager能量算子(Teager energy operator,TEO)的电缆故障定位方法。首先,利用改进的双端行波法消除波速对测距偏差的影响。然后,采用小波降噪法对采集的故障信号进行去噪。进一步应用EWT方法对降噪信号进行分解,提取降噪信号的高频分量。在此基础上,通过TEO能量曲线变化确定首端波头及近端反射波的到达时间,从而计算出电缆故障点到检测位置的距离。仿真结果表明,基于小波降噪和EWT-TEO的电缆故障定位方法对不同信噪比和故障电阻都具有良好的适应性和可靠性,能实现精确的电缆故障定位。展开更多
基金This work was funded by the project of State Grid Hunan Electric Power Research Institute(No.SGHNDK00PWJS2210033).
文摘The distribution network exhibits complex structural characteristics,which makes fault localization a challenging task.Especially when a branch of the multi-branch distribution network fails,the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network system.In this paper,the multi-branch mainline is decomposed into single branch lines,transforming the complex multi-branch fault location problem into a double-ended fault location problem.Based on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines,the endpoint reference time difference matrix S and the fault time difference matrix G were established.The time variation rule of the fault-traveling wave arriving at each endpoint before and after a fault was comprehensively utilized.To realize the fault segment location,the least square method was introduced.It was used to find the first-order fitting relation that satisfies the matching relationship between the corresponding row vector and the first-order function in the two matrices,to realize the fault segment location.Then,the time difference matrix is used to determine the traveling wave velocity,which,combined with the double-ended traveling wave location,enables accurate fault location.
文摘针对传统电缆故障定位法受波速和噪声影响导致的波头识别不准确及故障定位精度差问题,提出一种基于小波降噪、经验小波变换(empirical wavelet transform,EWT)和Teager能量算子(Teager energy operator,TEO)的电缆故障定位方法。首先,利用改进的双端行波法消除波速对测距偏差的影响。然后,采用小波降噪法对采集的故障信号进行去噪。进一步应用EWT方法对降噪信号进行分解,提取降噪信号的高频分量。在此基础上,通过TEO能量曲线变化确定首端波头及近端反射波的到达时间,从而计算出电缆故障点到检测位置的距离。仿真结果表明,基于小波降噪和EWT-TEO的电缆故障定位方法对不同信噪比和故障电阻都具有良好的适应性和可靠性,能实现精确的电缆故障定位。
