Surge Compression for Improved Fault Location Accuracy in Full Transient-Based Methods

Abstract

This paper proves that the accuracy of single-ended fault location techniques based on the correlation of fault transients in power lines can be significantly improved by inverse-filtering transients first. The reason for this improved accuracy is found in the reduction of the duration of the fault surge signal, thus increasing the sensitivity of fault-location metrics to the fault position. Reported results show that by using the proposed filtering strategy, faster sampling rates systematically and significantly improve the location accuracy, as opposed to the case when no filter is applied, for which virtually no improvement is observed. Because of its higher spatial selectivity, the proposed fault-location technique required the development of a new synchronization method, which ensures a precise transient synchronization without the need for high-speed sampling. It is concluded that by jointly using the proposed transient filtering and synchronization solutions, correlation-based fault location can be significantly improved even when using sampling rates as low as 100 kHz. Extensive numerical simulations for a three-phase transmission line confirm an improvement exceeding one order of magnitude in the fault location accuracy, for both low- and high-impedance faults.