A GNSS-independent Two-terminal Traveling Wave Fault Location Scheme for Transmission Lines

Two-terminal traveling wave-based fault location is essential for transmission line fault recovery. To synchronize the data, the traditional method relies heavily on the global navigation satellite system (GNSS), leading to a risk of signal error. Considering the propagation delay and time shift invariance of traveling waves, this paper proposes a two-terminal traveling wave fault location scheme without GNSS. In theory, this paper analyzes the influence of time synchronization error and the phase angle difference of the pre-fault directional traveling wave. The feasibility of two-terminal fault location by calculating pre-fault directional traveling wave phasor is proved by formula derivation. In algorithm, the proposed algorithm detects the arriving time of the initial current traveling wave by dyadic wavelet transform. Then, the directional traveling wave is processed by the discrete Fourier transform algorithm. Considering the transfer characteristics of Capacitive Voltage Transformers (CVT), the proposed scheme performs well under different fault conditions, sampling frequency and noise interference. Since no additional hardware is required, the proposed scheme could be conveniently integrated into existing devices. ©2024 Chin.Soc.for Elec.Eng.