精确检测故障行波信号是保证故障定位结果准确可靠的重要因素,针对Wigner Ville分布(Wigner Ville distribution,WVD)在检测故障行波时易产生交叉项的问题,提出一种基于改进变分模态分解(variational mode decomposition,VMD)和WVD的故障行波检测方法.首先,通过波形相似性确定VMD参数的选取,利用改进的VMD对线模行波信号自适应分解,实现对故障行波不同频段信号提取的同时保留重要故障信息;然后,分别求取各分量信号的WVD后叠加得到原始信号的WVD,由此解决WVD交叉项带来的影响;最后求取VMD-WVD能量谱密度分布,利用WVD良好的时频聚集性检测故障行波[150,170]kHz频段波头位置,从而实现故障行波波头的精准检测.仿真实验结果表明,该文所提方法相比小波和HHT的故障行波检测方法更加快速、准确.
Fault traveling wave detection method of distribution network based on adaptive VMD and WVD
Accurate detection of fault traveling wave signals is an important factor to ensure accurate and reliable fault location results. Aiming at the problem that Wigner Ville distribution (WVD) is prone to produce cross terms when detecting fault traveling waves, a fault traveling wave detection method based on improved variational mode decomposition (VMD) and WVD is proposed. Firstly, the selection of VMD parameters is determined by waveform similarity, and the improved VMD is used to adaptively decompose the line mode traveling wave signal, so as to extract signals of different frequency bands of fault traveling wave while retaining important fault information. Then, the original WVD signal is obtained by the calculation and superimposition of each component signal of the WVD, thus solving the influence of cross terms due to WVD. Finally, the energy spectral density distribution of VMD-WVD is obtained, and the good time-frequency aggregation of WVD is used to detect the wave head position from 150 kHz to 170 kHz frequency band of the fault traveling wave, so as to achieve accurate detection of the fault traveling wave head. Simulation results show that the proposed method is faster and more accurate than the wavelet and HHT fault traveling wave detection methods.
distribution networktraveling wave detectionimproved VMDWVD
万方数据
维普
