A New Scheme of Fault Location for Parallel Double-circuit Transmission Lines

This paper adopts GPS technology to implement time synchronization, propose a new double-circuit transmission line fault-location scheme . In order to obtain accurate results, the scheme considers the coupling effect between parallel lines and adopts the distribution line model. Based on the transmission line theory, the parameters of the distribution line model are extended by the third-order Taylor series. Determining the fault phases first, and then the healthy phases of the transmission line system can be ignored. The new fault location scheme can locate various types of faults (including evolving faults and cross-country faults), and has been tested in different fault points, different transition resistances, different fault initial angles and different fault types. In addition, the influence of different sampling frequency and parameter errors on the scheme is tested. This scheme avoids the influence of the healthy lines on the calculation of the fault distance and utilize accurate electrical signals, so the results are more excellent. The simulation study using MATLAB software and the max estimation error of fault location does not exceed 0.9056%.