Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line. A Parametric Analysis

When a substation is fed by a combined overheadcabletransmission line, a significant part of the ground faultcurrent flows through the grounded cable sheaths and dischargesinto the earth at the transition station, where cables are connectedto the overhead line. If the transition station is a dead-end steelpole structure, the local ground electrode, small and of highresistance, could be inadequate to maintain the ground potentialrise within safety limits in case of a fault to ground at thereceiving end substation. Based on a circuit model approach, thepaper presents a parametric analysis of the fault currentdistribution between the faulted substation and the transitionstation, taking into account of all the relevant parameters.