Traveling-Wave Fault Location Method Based On Dispersion Effect

At present, the power system scale is increasing and the voltage level is increasing, which is a higher requirement for the fault point and fault point. Compared with many traditional fault location methods, the traveling wave fault location method is based on the analysis of transient traveling wave signal, which is not affected by the transition resistance, system impedance and system operation mode.However, there are still some defects in the measurement of the arrival time of the wave head. When the frequency varying characteristics of the line parameters are considered, the different frequency components of the fault traveling wave signal have different attenuation and wave velocity. Therefore, the propagation of traveling wave will inevitably occur in the process of dispersion. In time domain, the dispersion of travelling wave is directly caused by the distortion of the wave front, which can be difficult to accurately determine the arrival time of traveling wave, so it can affect the accuracy of traveling wave fault location. In this paper, we propose a new method to enhance the singularity of the traveling wave signal based on the characteristic of the line parameters. By calculating the transmission coefficient of the traveling wave signal in a certain frequency band, the continuous system response is obtained by using the vector fitting method. And the correction method in wavelet domain compensates the original signal by using correction function in wavelet transform process.Both of the methods can eliminate or weaken the dispersion effect of the traveling wave in the transmission process, and improve the accuracy of the traveling wave fault location method.In the end of this paper, the simulation experiment is carried out in the ATP electromagnetic transient simulation program to build the transmission line model, and the MATLAB is combined with the simulation. The experimental results show that the method can improve the accuracy of the existing traveling wave ranging method, and can adapt to many kinds of fault conditions.