Measurement based fault location in three-terminal overhead line and underground cable

This paper presents a new fault location method for three-terminal composite network consisting of two overhead line sections and a cable. Synchronized measurements of three-phase current from all three ends and three-phase voltage - from the bus, where the fault locator (FL) is installed, are utilized for fault location. The fault location algorithm consists of three subroutines designated for locating faults within the respective line/cable sections and a multi-criteria procedure for selecting the valid subroutine. Generalized model of a fault loop are used for formulating the subroutines. Sample results of ATP-EMTP based evaluation are presented and discussed.