EQUATION SYSTEM CONCEPT FOR COMPUTATION OF GROUND FAULT CURRENT DISTRIBUTION WITH ELECTROMAGNETIC MODEL

Abstract

This paper describes the new equations system concept of electromagnetic model for computation of ground fault current distribution in electric power substations. We developed the new electromagnetic model based on applying the finite element technique to an integral equation formulation in the frequency domain. Model components can be located in homogeneous soil or in air. Model can take into account complete electromagnetic coupling between its components. Using known ground fault currents of adjacent substations, from which power substation hit by ground fault is supplied, in each of the adjacent substations one or more equivalent three-phase voltage sources are formed. Based on developed theoretical background, we also developed a software package, which is primarily designed for computation of ground fault current distribution. However, this software package can also be used for advanced analysis of current and voltage conditions on overhead power lines and underground power cables as illustrated by the examples.