Distributed Traveling-Wave-Based Fault-Location Algorithm Embedded in Multiterminal Transmission Lines

A novel traveling-wave-based fault-location algorithm for multiterminal transmission lines is introduced in this paper. Existing traveling-wave fault-location methods that based on the data measured at line terminals lack reliability and accuracy because time synchronization is needed, which brings error. To solve this problem, the complex structure of multiterminal power system is divided into several fault identification branches, current at the midpoint of each branched is measured, a novel fault-location algorithm is proposed, and the time synchronization error is eliminated. A line-based device is designed to measure the current at the midpoint of each branch. An accurate value of the traveling wave speed can be obtained by merely applying the data record in one measuring device. Thus, the fault-location accuracy is improved. The system model applied in this paper comprises one transmission line and two tapped lines, and the proposed method applies to networks with more terminals. Performance of this method is tested by different cases by PSCAD. The hardware platform has been tested in Sichuan Province, China.