Travelling wave fault location applied to high-impedance events

Because the market regulation in Brazil, power transmission companies are paid for the availability of their lines. When a fault occurs and the line becomes unavailable, such companies are penalized for the time the line is off-service. Thus, fault location systems that can reach higher accuracy to estimate the fault location minimize the downtime of the line and, therefore, the application of penalties. Impedance-based fault location methods usually are not efficient in high-impedance events. Travelling wave-based fault location technology provides good estimation independently of the type of the fault. This presentation shows the experience of implementing a travelling wave-based fault location system in Eletronorte (Brazil) transmission lines, which, because of their geographical location and the climate of the region, have a large incidence of high-impedance faults. After a large number of events, the results show the reliability of fault location by using travelling waves, even if the wave fronts are shown with higher attenuation compared to those produced by low-impedance faults.