摘要
鉴于输电线路在线监测取得了长足的进步,针对目前行波定位法中波头检测算法存在缺陷和波速测定精度差的不足,本文提出了基于导线电流三测量点局域均值分解(LMD)的行波故障定位新方法。该方法首先对测量点电流线模分量进行局域均值分解,然后根据分解得到的第一个PF分量瞬时频率曲线的首个频率突变点来确定行波波头第一次到达测量点的时刻。其次,根据相位差动保护原理判断出故障点所在线路段,并利用无故障段线路的长度和故障行波到达其两端测点的时间差之比计算出故障行波波速。最后,通过双端行波法的定位原理计算出故障距离。仿真结果表明,本文定位方法同基于小波变换或希尔伯特-黄变换的定位方法相比具有较高的定位精度。
As much progress has been made on the on-line monitoring of transmission lines,a new fault location scheme for transmission lines is proposed in the paper based on local mean decomposition（LMD） on fault current traveling waves of three measurements.It can reduce the calculating error on the propagation velocity of the traveling wave comparing with existing traveling wave schemes for fault location.It works in the following main steps.Firstly,the local mean decomposition is applied to aerial mode component of each measured current wave,and the arrival time of the initial traveling wave can be detected according to the first sudden arising of frequency in the instantaneous curve of the first product function（PF） obtained through LMD.Secondly,the faulted segment is determined through comparing the phase angles of measured currents at two ends of a line segment,and the wave velocity of the fault current is obtained by the ratio of the length of healthy line segment to the difference of the time that the wave travels through this segment.Finally,the fault point can be determined according to the two-terminal traveling wave fault location formula.Fault location simulations were done with all kinds of faults in a power line based on the proposed scheme.The results show that it has higher fault location accuracy than the schemes based on either wavelet transform or Hilbert-Huang transform.
出处
《电工技术学报》
EI
CSCD
北大核心
2012年第3期260-268,共9页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(60974125)
关键词
故障定位
行波
局域均值分解
输电线路
Fault location
traveling wave
local mean decomposition
transmission line
