The Application Study On Transmission Line's Fault Detection And Location Based On Wavelet Transform

This paper analyzes the transient state processing of the power system, and theoretical analysis and simulation results show the shortage of the Fourier Transformation and Short-time Fourier Transformation in the fault detection of power system transmission lines; also this paper summarizes the methods of fault location of the transmission lines at present. Aimed at the key problem of traveling wave location-accurate extraction of fault times, a new method using the wavelet transform is brought out which can detect and analyze the transient fault signals. The practical problems in the fault detection and fault location using the wavelet transform, such as the wavelet basis function, the initial data, the velocity of traveling wave are studied. According to the model of practical power system transmission line, simulation results show that the wavelet analysis is availability and accurate in the traveling wave fault times extraction.Fault signals and noise signals appear different feature in the wavelet transforms. According to the shortage of fault detection algorithms at present, a development algorithm in order to solve the short of general algorithm at present is introduced to meet demands of fault detection in the noise environment. The algorithm, which multiplies the corresponding wavelet coefficients of adjacent fine scales, enhances the feature of discontinuity point of signals and inhibits the effect of noise signals. Results of theory analysis and power system transmission lines simulations show this method is effective.The second-generation wavelet transform has being a hotspot in recent years for its merits, such as the simplicity of algorithm, the independence on the Fourier Transform and the ability to realize integer wavelet transform. This paper carry through a primary research in fault feature extraction of the transmission lines using the second-generation wavelet transforms.