Automatic determination of fault current breakpoint locations for personnel protective grounding of distribution and transmission lines

Abstract

Personnel protective grounding of overhead distribution and transmission lines is a required safety practice involving field personnel using grounding wires to de-energize lines prior to working on the lines. The purpose of this investigation is to create an automatic process that determines the possible fault currents at all locations of transmission lines to help guide field personnel through selection of grounding wires that are appropriate for the level of the fault currents at corresponding locations. When the power system topology changes, the fault currents at different locations of the lines change. The automation updates the information and contributes to safer environment for field personnel. ASPEN OneLiner, a short-circuit analysis program, was used to perform sliding fault analysis - a series of short circuits placed at incremental distances between the two endpoints of a transmission line resulting in a current profile that shows the fault current level as a function of distance along the line. The paper includes a case study that demonstrates practicality of the method for simulation and analysis of power systems.