The Research Of Method In Single-ended Fault Location With Transient Current Traveling Wave In The High Voltage Transmission Line

The accurate fault location of the fault position of high voltage transmission line is principal measure for improving safety and economic performance of the power restoration of line , cut down economic loss due to the failure ,which has great social and economic interests.The merits of single terminal fault location are its reliability and its accuracy isn't affected by the type of line, fault resistance and two sides systems theoretically but this method has problems such as the identification of reflection wave and the unidentifiable area of reflection nearby which are research purpose and core of this paper.On the basis of extensive reading and research of theory of the wavelet, it is presented a practical method based on odd theory of wavelet analysis to remove the white noises from transient fault current traveling waves of high voltage transmission line via multi-size analysis of wavelet. The basic start point is by analyzing the difference characteristics of signal's odd point and white noise under multi-size change of wavelet to gain simple criterion and arithmetic .The advantage is of improving the signal-noise rate, on the same time increasing the resolution of transient signal arrive at the aim of pre-processing of the fault classification and recognition.By analyzing the refraction,reflection process of fault transient current traveling wave of high voltage and characteristics of refraction ,reflection coefficient systematically, a new fault location method of single ended traveling wave is presented. It can not only identify the reflection wave for fault location efficiently, but also not be affected by the structure and length of line. Fault earthed resistance ,fault type ,system impedance and can locate fault in adjacent areas accurately. The low-pass digital filter is designed by simulating the feature of . The traveling wave of transient fault current of low-pass digital filter is analyzed again and the fault is located by the single ended traveling wave fault location method is valid in practice. It is also wavelet transformation that transient wave formed in the charged process of line, the accurate length of line can be got by using singularities and idea of fault location presented in the paper.