Singularity point detection of high frequency signal for fault location

Traditionally the singularity point in extreme scenarios such as weak traveling waves may not be detected accurately as a result of their small amplitudes and naturally-existing attenuation. In this paper, a novel method based on curve fitting theory for singularity detection for extreme scenarios (weak traveling waves) is proposed, which considers both the characteristic of traveling waves and the influence of distributed capacitance at the bus bar. Mathematical equation of rising edge of the initial traveling wave is deduced in this paper. Furthermore, the indirect mathematical equation based on Maclaurin expansion theory is derived to improve its feasibility in the real application. Combining the indirect equation and the measured traveling wave data, the least-square algorithm-based fitting curve can be obtained to determine the singularity point. The proposed method´ s efficiency in detecting the singularity point in weak traveling waves has been verified. The simulation results show that the proposed method had improved the accuracy and robustness of singularity point detection for weak waves significantly.