New Method of Locating Faults on Three-terminal Lines Equipped with Current Differential Relays

This paper presents a new method for locating faults on three-terminal power lines. Estimation of a distance to fault and indication of a faulted section is performed using three- phase current from all three terminals and additionally three- phase voltage from the terminal at which a fault locator is installed. The fault location algorithm consists of three subroutines designated for locating faults within particular line sections and a procedure for indicating the faulted line section. Testing and evaluation of the algorithm has been performed with fault data obtained from comprehensive ATP-EMTP simulations. Sample results of the evaluation are reported and discussed.