Applications Of Wavelet Transform In Traveling Wave Fault Location Of Transmission Line

With the development of power grid, the voltage grade and capacity of transmission lines improve gradually. Transmission line fault has more and more influence on social and economic life. Transmission line fault location device not only provide accurate, reliable fault location information for transmission patrol, reduce load of field staffs, shorten outage time, but also useful to find the weakness of transmission line early, effectively reduced by the blackout caused economic losses. Therefore, the fault location device of transmission line is a important technical measures for ensuring grid security, stability and economic operation.This paper first introduce wavelet theory including:continuous wavelet transform, discrete wavelet transform and binary wavelet transform, discussing the characteristics of wavelet transform. The definition, generation, fast decomposition algorithm and the decomposition scale selection of the cardinal B-spline derivative wavelet is also introduced in the paper. Secondly, the processing of fault transient traveling current wave is presented in the paper, The effect and corresponding solutions of such factor is presented in the paper for example:branch line number, short circuit transition resistance and so on. And then, the single terminal fault location algorithm and its implementation steps is introduced in the paper. The EMTDC simulation is adopted to verify the algorithm in paper. Considering the characteristic of single terminal fault location algorithm is of high accuracy, low reliability. The reflected wave recognition method based on the length of line is presented in paper, the EMTDC simulation data shows:compared with the prior reflection wave identification method, identification success rate of reflection wave identification is improved by method described in papa. Finally, the single terminal fault location algorithm and its implementation steps is introduced in the paper. The EMTDC simulation is adopted to verify the algorithm in paper. Considering the characteristic of single terminal fault location algorithm is of high accuracy, low reliability. The reflected wave recognition method based on the length of line is presented in paper, the EMTDC simulation data shows:compared with the prior reflection wave identification method, identification success rate of reflection wave identification is improved by method described in paper.