Accurate Single-End and Double-End Fault Location by Traveling Waves: a review with some real applications

Traveling Wave -based fault locators (TWFL) are an accurate method to locate a fault within a tower span and offer significant benefits to utilities by reducing the time and cost of repairing and preventing reoccurrence of faults. Double-ended TW fault locators (DETWFL) use a simple operating principle but require communications between two Intelligent Electronic Devices (IEDs) and a common time reference. Single-ended TW fault locators (SETWFL) eliminate the need for the communications channel and common time reference, but their operating principle is more complex. They are less expensive and are exposed to less errors sources or failures. This paper discusses two practical application cases of TWFL, the first based on DETWFL and the second on SETWFL. The first case illustrates how the two-terminal TWFL method can be extended to multiterminal and hybrid lines, including multiterminal lines with a combination of overhead conductor and underground cable sections. The second case describes a SETWFL method that uses only local line currents. This method uses the impedance based FL results to find the approximate FL and then refines the results using TW measurements.