Time reversal applied to fault location in power networks:pilot test results and analyses

This paper presents the results of a pilot test performed on a real medium voltage distribution network in Switzerland with the aim of assessing the performance of a fault location system relying on the Electromagnetic Time Reversal (EMTR) method. To the best of the Authors’ knowledge, this is the first time that the EMTR-based fault location technique is validated through live tests. The pilot network is a live radial medium voltage distribution feeder, which consists of 11.9-km long double-circuit lines operating at 18/60 kV and multiple 18-kV three-phase laterals. The branched lines are overhead lines, underground cables, or mixed configuration with lengths ranging from tens of meters to a few kilometers. The test involves solid- and resistive-type single-phase-to-ground fault occurrences triggered along one of the laterals when the network is operational. The fault location task is performed by a real-time industrial controller prototype that integrates the functions of fault detection, data acquisition, time-reversal processing and Electromagnetic Transients simulations. Concerning the methodological aspects, the EMTR Fault Current Signal Energy (FCSE) metric is used to determine the location of the fault. The obtained results show that the FCSE metric is capable of accurately identifying the faulty phase and the real fault location in all tested fault cases, with a location accuracy of less than 10 m.