A wavelet multiresolution-based analysis for location of the point of strike of a lightning overvoltage on a transmission line

Lightning flashes on extremely high voltage lines are quite common and can lead to insulation breakdown or other line hardware failure causing disruption in supply. An accurate location of the site of failure will result in faster maintenance and restoration of supply. In this paper, a novel technique based on the wavelet multiresolution analysis (MRA) for locating the point of strike of a lightning overvoltage on a transmission line is presented. Lightning strikes at different points on a 400-kV transmission line of different line lengths are simulated by shifting the point of strike of the lightning impulse every 5 km. The Electromagnetic Transient Program (EMTP) [Microtran] is employed to generate the time-domain input signal. Daubechies eight (D8) Wavelet transform is used to analyze lightning overvoltages. The tenth level output of MRA detail signals extracted from the original signals is used as the criterion for the analysis. Extensive simulation work has been done and results indicate that the proposed scheme is very effective in locating the point of strike with reasonable accuracy.