Calculation of conductive effects on earth return circuits

The paper presents an analytical-numerical solution for the potentials and currents excited along buried conductors (earth return circuits) by the conductive effects of the quasistationary electric flow field produced in the earth by earthing arrangements. It is assumed that the system considered is linear and that the earth is an isotropic, homogeneous medium of finite conductivity. The reaction of currents floating in the underground conductor on the currents in the earthing devices is disregarded. The transmission line model of the earth return circuit, a segmental approximation of the curve of the primary potential distribution along the conductor and the concept of superposition have been used in the method. The method may be useful for an evaluation of the conductive effects on the earth return circuits in many practical cases, which are connected with power supply systems, electric traction and cathodic protection as well. The technical application of the method presented is illustrated by an example.