EMD-Denoising Signal Applied to Traveling Wave-Based Fault Location in Radial Distribution Systems

For applications in power system protection and fault location, it is crucial to remove noise to ensure proper functioning. Many studies have addressed the extraction of noise from signals using filters based on the wavelet transform. This study proposes a filter, where an adaptation of the thresholding function is proposed to smooth out the peaks originating from residual noise after reconstructing an original signal. This theory is used together with a fault locator method based on traveling wave theory. The proposed approach was validated through simulations in the PSCAD™/EMTP™ software in a medium voltage radial distribution system (CIGRE). The results were analyzed for different noise levels (30, 40, 50, and 60 dB), considering their effects on the proposed methodology. The results were satisfactory for noise levels above 40 dB, with an average relative error ranging from 0.12% to 1.83% (with a standard deviation of 0. 45% and 0. 83%) in estimating fault distance.