Fault location algorithm for partial coupling four-parallel lines under different voltage levels

In this study, a novel fault location algorithm applicable to the partial coupling four-parallel lines is presented. In this method, the occurrence of differential positive-sequence currents at local end are used to select the two parallel lines whose electrical data measured will be used to calculate the fault location. Then two objective functions established based on the assumption that the fault occurs at different line part are used to derive a optimization problem. The line part and location of fault are simultaneously obtained by solving this problem. This algorithm is immune to fault resistance and only needs the synchronous current data from both ends of the two lines under same voltage level including faulted line. Simulation results show that this proposed algorithm can calculate the fault location accurately, when different types of faults at different locations occur in partial coupling four-parallel lines.