Fault location method based on edge detection for low SNR traveling waves

Abstract

Accurate fault location methods can greatly reduce the power recovery time, which has an important effect on the power supply reliability. Fault location methods have been extensively studied; however, location for high impedance faults and faults with near-0° fault angles or low signal-to-noise ratio (SNR) transient waves remain challenging. In this paper, a fault location method based on edge detection is proposed. This approach extracts fault features using the Canny operator and determines the fault inception time using the Otsu threshold. The algorithm is described using the noise-free and noisy fault waveforms as examples. The parameters in the algorithm can be adaptively adjusted according to the frequency and SNR of the fault waveforms. A 500 kV AC transmission line was built to compare the performance of the proposed method with that of the fault location method based on the wavelet modulus maximum under different conditions of fault resistance, fault position and fault angle. The results show that the proposed method not only has a better location accuracy under typical fault conditions, but is also more robust for faults with low SNR traveling waves such as those with high fault resistances and near-0° fault angles.