Design and implementation of a robust fault detection mechanism for EHV lines

This paper presents a robust fault detection mechanism in EHV lines by using Wavelet transform and FFT analysis. db6 is chosen as mother wavelet since it is best one to analyze the transients during faults and load switching. The simulated results are validated with the experimental results. For fault detection 2nd harmonic spectral component and energy difference of the consecutive windows are used as deciding parameters for fault detection. The algorithm is robust such that it won't issue trip signal for the load changes. But in the case of any fault in the system (LG fault in this paper) both second harmonic and difference of energy of consecutive windows exceeds threshold value and issues trip signal. The status of the transmission network is monitored in a mobile application developed for android.