在行波故障测距法中,对准确提取行波波前到达时刻的信号处理方法的研究一直是重点和难点。该文提出一种基于提取故障线路自然频率的单端测距新方法。在输电线上传播的行波在频域上表现为一个特定频率的谐波形式,称为行波的自然频率。采用复小波对故障后电流或电压信号进行连续小波变换,再对小波参数进行后处理以提取主自然频率,结合行波在该频率的波速,计算得出故障发生的距离。运用该算法对大量故障仿真实例进行了分析,结果验证了算法的可行性及其精度。
The research on signal processing techniques to detect the accurate wavefront arriving instant is both important and difficult in traveling wave fault location techniques. A new single ended fault location method of extracting faulted line natural frequencies is described. The frequency spectra of the travelling waves propagating on transmission lines are of harmonic type of a fundamental characteristic frequency, called natural frequencies. Using continues complex wavelet transformation and proper post-processing method the natural frequencies can be extracted from post-fault currents or voltages and be used to calculate the fault distance. The algorithm has been tested for a large amount of simulation cases. The results confirm its feasibility and accuracy.