一种基于小波变换的超高压线路故障选相方法

为了在超压线路发生故障时能够实现快速选相，基于故障行波的特点和小波变换的奇异性检测原理，提出了一种故障选相方法。由各种故障类型的边界条件，经过相模变换公式推导出故障点电流各模分量小波变换的模极大值满足的基本关系，得到选相简化判据并进行了改进。仿真表明，该选相方法对任何故障相角、过渡电阻、故障位置处发生的各种类型故障都能准确识别。

A scheme of faulted phase selection in EHV transmission line based on wavelet transforms

In order to realize fast phase selection when fault occurs in EHV transmission line, a scheme of faulted phase selection is proposed based on the features of faulted traveling waves and the singularity detection principle of wavelet transforms. According to the boundary conditions of fault types, the basic relationship meeting the wavelet modulus maxima of each mode component is deduced by the phase-mode transformation formula, and a simplified phase selection criterion is obtained and improved. Simulation results show that this phase selection scheme can detect faulted phase accurately for various fault types at any conditions involving different fault inception angle, fault resistance and fault position.