A FAULT LOCATION TECHNIQUE FOR RURAL DISTRIBUTION FEEDERS

This paper presents a digital fault location technique for rural distr ibution feeders, using the voltage and current data at a single locati on. Rural distribution feeders include single-phase, two-phase, and th ree-phase laterals off a main three-phase primary distribution feeder. The fault location scheme presented here attempts to account for the multiphase laterals, the unbalanced conditions, and the unsymmetrical nature of distribution feeders by continually updating voltage and cur rent vectors at set locations within the system. The updated voltage a nd current vectors are the estimates of the 60 Hz phasor quantities ob tained using a recursive optimal estimation algorithm. The distance to the fault is then estimated using a method based on the apparent impe dance approach and the updated voltage and current vectors. Another co nsideration is the ability to determine the fault location on a latera l. A simulation of an actual rural distribution feeder using the Elect romagnetic Transients Program (EMTP) is used to illustrate the concept s of the approach.