基于改进消失矩复小波的输电线路故障测距

针对输电线路故障测距时所使用实小波变换结果是实数、缺乏相位信息以及频带混叠等缺陷,提出利用改进消失矩的高斯复小波处理故障信号。首先,分析消失矩对小波时频域的影响;然后,从故障信号的奇异性出发,分析辨识奇异性的Lipschitz指数与消失矩的关系,提出消失矩的改进判据;最后,利用高斯复小波对输电线路故障信号进行处理,根据变换结果中的邻幅比和相位畸变率而选取最优消失矩。仿真和实验表明,笔者提出的改进消失矩高斯复小波增强了信号奇异性检测能力,有效地抑制了干扰,使其减少17.84%,并稳定了相位信息,使相位畸变率减小4.12%。同时,改进消失矩复小波测距结果的误差比普通消失矩的高斯复小波的测距结果误差减少6.06%,比实小波测距结果误差减少5.82%。

Position Fault of Transmission Line Based on Improved Vanishing Moment Complex Wavelet

Owing to the result of the real wavelet transform is real number, which lacks phase information and the frequency spectrum band exists phenomenon of aliasing, when the real wavelet is used to position the transmission line fault. An improved vanishing moment Gauss complex wavelet is proposed, and which is utilized to analyze fault signals. Firstly, how to change wavelet in time frequency and magnitude frequency by vanishing moment is analyzed; then, the relationship between Lipschitz index and vanishing moment is obtained by research singularity of fault signal, and a criterion is proposed to improve vanishing moment; eventually, fault signal is analyzed by Gauss complex wavelet, and the vanishing moment is optimized by adjacent magnitude ratio and phase distortion ratio. Simulation and experiment show that improved vanishing moment Gauss complex wavelet enhances distinguish ability for singular signal, which not only restrain the interference effectively and decrease it about 17.84%, but also reduce the phase distortion rate in phase information by 4.12%. Meanwhile, the error of improved method decreases by 6.06% compared with ordinary Gauss complex wavelet, and decreases by 5.82% compared with real wavelet.