基于经验小波变换的混合输电线路单相接地故障测距

针对架空线-电缆混合输电线路波阻抗不连续而引起的频谱混叠现象严重的问题,提出了一种基于经验小波变换(EWT)的混合输电线路单相接地故障测距方法.首先利用EWT对故障产生的暂态零序电流行波分解得到低频分量.然后根据低频分量选线判据对混合输电线路进行故障选线,通过分析奇异性检测结果准确标定故障线路行波波头.最后配电网混合输...

Single-phase to ground fault location of hybrid transmission lines based on empirical wavelet transform

To solve the serious problem of spectrum aliasing caused by discontinuous wave impedance routing of an overhead-cable hybrid transmission line, a single-phase ground fault location method based on Empirical Wavelet Transform (EWT) is proposed. First, the EWT is used to decompose the transient zero sequence current traveling wave generated by the fault to get the low-frequency component. Then, fault line selection of the hybrid transmission line is carried out with a low-frequency component line selection criterion. By analyzing the singularity detection results, the traveling wave head of the fault line is accurately calibrated. Finally, the fault location of hybrid transmission lines in distribution networks is realized by the principle of single-terminal traveling wave location. PSCAD/Matlab simulation results show that the method has high accuracy, and the fault location accuracy is within 200 m, which meets the requirements of engineering practice.This work is supported by the Key Research and Development Program of Gansu Province (No. 18YF1FA058) and Lanzhou Talents Plan (No. 2017-RC-95).