Fault Data Synchronization Using Wavelet for Improving Two-terminal Fault Location Algorithm

Fault data synchronization for improving Two-terminal fault location algorithm is proposed. Conceptually, employing Wavelet technique, the instantaneous currents of both ends, sampled by Digital Fault Recorders (DFR), will be used to determine a transient reference point for synchronizing the DFR data before applying the Two-terminal algorithm. In the study, both symmetrical and unsymmetrical faults have been simulated for a simplified 230 kV transmission system. The case studies of applying Two-terminal fault location algorithm to the simulated unsynchronized sampled data with assumed phase-shift error varying from -180 to 180 degree, and to the corresponding synchronized data using the proposed Wavelet technique with fixed threshold are conducted for performance verification. Additionally, the effect of fault resistance in the range of 0.01 50 ohm has been investigated. In all test cases, the proposed synchronization method yields satisfactory results such that the error of fault location is independent of the phase-shift error.