The Research Of Traveling Wave Fault Detection Based On Wavelet In Transmission Line

The power system is a pillar of national economic development and the construction of an extremely important role in the national production and daily life. In the power system, transmission lines charged with the important task of the power transmission is connected to the bridge of the power plants and power users, electric power system is also prone to failure in one of the links. Therefore, timely, accurate, reliable detection and location of transmission line fault on the safe and stable operation of the electricity network, reduce the economic losses caused by line fault is of great significance.Transient traveling wave signal generated by the line fault to fault location with fast, accurate, and this paper, wavelet theory, put forward a new method of fault detection. First of all, on the basis of the commonly used wavelet threshold de-noising method to improve the semi-soft threshold de-noising method using the method of noise reduction to get the reconstructed signal distortion, can be more effectively reduce the noise; Secondly, the use of grid analysis of the transient equations of the fault line, and use the signal singularity detection of wavelet transform modulus maxima theory, transmission line fault transient current traveling wave detection, and extract the measured traveling wave signal wavelet transform modulus maxima, and in order to determine the exact moment of the occurrence of line fault; Again, the use of single-ended traveling wave fault location to improve the algorithm to calculate the distance to fault, and can effectively eliminate the traveling wave dispersion positioning accuracy ranging more accurate and reliable; Finally, the transmission line model based on the actual power system using wavelet toolbox of Matlab7.0and the PSB power system simulation tools, different fault types and transition resistance of several short-circuit fault simulation experiments and experiments the results compared with traditional methods. The experimental results confirmed that the A-type traveling wave fault location algorithm using wavelet transform method for improvements in single-ended fault location accuracy has improved greatly, ranging accuracy to meet the site requirements for accurate fault location.