High-impedance fault detection utilizing a Morlet wavelet transform approach

An application of Morlet wavelets to the analysis of high-impedance fault g enerated signals is proposed in this paper. With the time-frequency localiz ation characteristics embedded in wavelets, the time and frequency informat ion of a waveform can be presented as a visualized scheme. Different from t he fast Fourier transform, the wavelet transform approach is more efficient in monitoring fault signals as time varies. The proposed method has been a pplied to discriminate the high-impedance faults from the normal switching events, and to examine the faults under various grounds including Portland cement, wet soil and grass. Testing results have demonstrated the practical ity and advantages of the proposed method for the applications.