基于同步挤压小波变换的故障行波测距方法

针对输电线路故障行波波头识别困难、易产生频谱混叠的问题,提出一种基于同步挤压小波变换(SWT)的故障测距方法。利用SWT提取故障行波小波脊线,生成一组内蕴模态类函数分量(IMTs)。然后对IMTs进行Hilbert变换提取故障点特征量,进而标定首波头的到达时刻。最后根据双端测距原理计算出故障距离。与传统的希尔伯特_黄变换和小波变换相比,该方法实现了故障行波波头较高精度的识别和对频谱混叠的有效抑制,具有较高的测距精度,对噪声的鲁棒性更强。PSCAD仿真验证了该方法的有效性,且测距结果受故障距离和过渡电阻的影响较小。

Fault traveling wave ranging method based on synchrosqueezing wavelet transform

Aiming at the problem that the fault traveling wave head of transmission line is difficult to identify and easy to generate spectrum aliasing in fault location, a fault location method based on Synchrosqueezing Wavelet Transform (SWT) is proposed. The SWT is used to extract the wavelet ridges of fault traveling wave to generate a set of Intrinsic Mode Type functions (IMTs). Then, the Hilbert transform is performed on the IMTs to extract the feature points of the fault point to achieve the purpose of calibrating the arrival time of the first wave head, and finally calculate the fault distance according to the double-ended ranging principle. Based on the accurate modal decomposition capability of SWT, the recognition of the high accuracy of the faulty traveling wave head and the effective suppression of spectral aliasing are realized. Compared with the traditional Hilbert Huang transform and wavelet transform, this method achieves high accuracy recognition of faulty traveling wave head and effective suppression of spectral aliasing. It has high ranging accuracy and is more robust to noise. The PSCAD simulation verifies the effectiveness of the proposed method, and the ranging result is less affected by the fault distance and transition resistance. This work is supported by National Natural Science Foundation of China (No. 71771111) and Guiding Program of Liaoning Natural Science Foundation (No. 201805500438).