Customized wavelets for improved fault location quality in power systems

A procedure for generating customized wavelets for detecting the location of a fault along the length of a transmission line is proposed. Measuring the time-difference-of-arrival (TDOA) between two consecutive transient reflections or the TDOA between the two initial peaks of two synchronized voltage/current bus measurements provides an accurate fault location estimate. Highly accurate TDOA estimates can be obtained only when the processed fault waveform consists of short/peaked pulses that arrive on a bus with a small group delay. Our customization procedure enhances the “peakedness” and shortens the group delay of the transient waveform by optimizing a suitable peakedness metric. This approach yields more accurate estimates than the “classic” (Daubechies) wavelet-based techniques found in the literature. The proposed method is independent of the fault-type and can be used to reduce the required data sampling rate while maintaining reliable TDOA estimates.