瞬时零序功率全频带小波能量熵故障选线

Fault Line Selection of Instantaneous Zero-Sequence Power Full-Band Wavelet Energy Entropy

针对传统的故障选线方法缺陷,本文提出了基于瞬时零序功率的全频带小波能量相对熵小电流接地系统故障选线方法。首先,利用小波变换方法对故障后各出线的瞬时零序功率的采样数据进行多尺度小波分解;然后,对各尺度小波系数进行单支重构,构造出各条出线的全频带小波能量相对熵矩阵,并计算综合小波能量熵;最后,依据矩阵中各条出线的综合小波能量熵的大小进行故障选线。仿真结果表明,该故障选线方法具有很强的适应性,可以在各种情况下使选线正确率达到100%。

In the low-current grounding system with multiple outgoing lines,this paper proposed a fault line selection method based on instantaneous zero sequence power for the full band wavelet energy relative entropy of low-current grounding system.Firstly,the sampling data of the instantaneous zero sequence power of each outgoing line after the fault was decomposed by multi-scale wavelet.Then,the wavelet coefficients of each scale were reconstructed on a single branch,the full-band wavelet energy relative entropy matrix of each outgoing line was constructed,and the comprehensive wavelet energy entropy was calculated.Finally,fault line selection was carried out by comparing the total wavelet energy entropy of each outgoing line in the matrix.The simulation results show that the fault line selection method has strong adaptability and can make the line selection accuracy up to 100%in all cases.