Time-domain fault location algorithm for parallel transmission lines using unsynchronized currents

Parallel transmission lines under fault can be decoupled into common component net and differential component net. For the differential component net is only composed by parallel lines part and its bus voltages are zero, the voltage distributions along differential component net can be calculated by each terminal current. The novel time-domain fault location algorithm is founded by voltage distributions from both terminals have the least difference at the fault point. The synchronization is achieved by searching the minimal value of locating criterion function, which is calculated by fixing one terminal data and moving another terminal data within a setting time. The proposed algorithm needs a very short data-window, any segment of fault data front transient to steady state can be used to locate faults, and no voltage data is needed. With distributed parameter model, simulations show that the locating errors are less than 0.1 km, and the fault types and fault resistances have no effect on locating accuracy. (C) 2005 Elsevier Ltd. All rights reserved.