Traveling Wave Fault Location for Lines Combined with Overhead-Lines and Cables Based on Empirical Wavelet Transform

D-type fault location method commonly used for hybrid line fault location is susceptible to the problem of asynchronous time difference of detection points, this paper proposes a single terminal fault location method for hybrid lines. Firstly, the segmentation criterion is constructed by using the feature of zero mode and line mode wave velocity difference, and then the fault location is completed by the single terminal method of zero mode and line mode wave speed difference. EMD can realize adaptive decomposition of traveling wave signals, but there is a problem of mode aliasing. Aiming at this problem, this paper proposes a traveling wave detection method based on empirical wavelet transform, which decomposes the fault traveling wave signal by EWT, and then uses the high frequency EMF2 component to accurately calibrate the traveling wave head. A large number of simulation results show that the fault location results of the proposed method are accurate and reliable.