基于Hilbert-Huang变换的行波法高压输电线路故障定位

摘要

When a short circuit fault of transmission lines happens, it will produce transient state traveling wave, which is a non-linear and non-stationary signal. To accurately extract the wave head is the key to traveling wave fault location. This paper applies Hilbert-Huang transform, a non-stationary signal processing tool, to detect the wave head to realize fault location. Make use of GPS to synchronously acquire the current signals at both ends of the transmission lines before and after the fault happened. The high frequency modal component can be obtained after Empirical Mode Decomposition (EMD) for these signals. And then we can get a time-frequence figure by Hilbert Transform from the high frequency modal component. The mutational site of the frequence on the figure is the arrive time of the wave head. The results of simulations by Matlab show that this method can accurately extract the arrive time of wave head, and also has high accuracy.%输电线路发生短路故障时,产生的故障暂态行波是一种非线性、非平稳信号.准确提取行波波头信号,是行波法故障定位的关键.将Hilbert-Huang变换这一非平稳信号处理工具应用于故障行波波头的检测,实现故障定位.利用GPS同步采集输电线路双端故障前后一段时间的电流数据,对其进行经验模态分解,将得到的高频模态分量进行Hilbert变换,得到相应的时间-频率谱图.时频图上的频率突变时刻即为行波波头的到达时刻.Matlab仿真结果表明,该方法能准确捕捉行波波头的到达时刻,有较高的定位精度.