基于Hilbert-Huang变换的电网故障行波定位方法

正确辨识和检测故障行波信号是实现电网故障行波定位的关键.提出了一种新的故障行波信号时频分析方法,采用Hilbert-Huang变换(HHT)对故障行波信号进行检测,通过经验模态分解(EMD)法提取故障行波信号的固有模态函数(IMF),再进行Hillaert变换,得到各自的瞬时频率,由瞬时频率进行行波到达时刻的准确检测.HHT与小波变换比较,不存在变换参数的选取难题,变换结果具有唯一性.仿真结果表明HHT能更准确地提取电网故障行波波头位置,有效提高故障行波定位精度.

Power Grid Faults Location with Traveling Wave Based on Hilbert-Huang Transform

Identification and detection of faults traveling wave are very important for power grid faults location.A novel time-frequency analysis method for the traveling wave signals is proposed.Hilbert-Huang transform(HHT)is applied to detect the signals.Intrinsic mode functions(IMF)of traveling wave are extracted by the empirical mode decomposition(EMD),and then Hilbert transform is used to calculate the corresponding instantaneous frequency of each IMF component.The arrival time of traveling wave can be detected by the instantaneous frequency.Compared with the wavelet transform,it is not necessary to select parameters in HHT,and the transform has only one result.Simulation results show that the HHT is more exact to extract the arrival time of traveling wave,and the precision of fault location is in range of practical acceptance.