Electromagnetic wave propagation along conductors parallel to interfacing homogeneous half spaces

This thesis explores electromagnetic wave propagation along single and multi-conductor systems consisting of bare and insulated wires located arbitrarily on either side of interfacing homogeneous half spaces. Equations are derived from first principles to predict the behavior of such systems across the full electromagnetic spectrum. The proposed full spectrum equations extend existing theory to include magnetizable earth and conductors with finite conductivity. They also offer a full spectrum solution for the excitation of conductors located either side of the interfacing half spaces for the first time in published literature. The proposed full spectrum equations are limited to homogeneous earth, and bare and insulated cylindrical conductors but remain general in every other sense. Novel expressions for the continuous modes of the systems have also been developed from these equations. Numerical investigation of the proposed full spectrum equations identifies numerous new discrete modes of propagation for single conductor systems, several with very low attenuation constants that may have industrial application. The modes associated with the full spectrum performance of two conductor systems consisting of parallel conductors located arbitrarily across the interface between the homogeneous half spaces energised by a delta-gap voltage source has been investigated in detail for the first time. Based on the numerical results conditions for which the full spectrum system performance may be approximated by the discrete Transmission Line mode are considered. The proposed full spectrum equations are shown to reduce to the quasi-TEM mode approximations that are Carson and Pollaczek's original solutions to the problem, bringing the understanding of the quasi-TEM mode approximations in line with the full spectrum solutions so that it may be adequately applied to power system safety. The conditions under which this may occur are clearly documented. Alternate quasi-TEM mode approximations are proposed in an analytical form. The assumptions required to reduce these alternate quasi-TEM mode approximations to Carson and Pollaczek's original solutions are detailed, making them, for the first time, a full set of analytical equations that are exact solutions to Carson and Pollaczek's equations. The analytical solutions provide the benefit of improved stability and reduced computation time with respect to numerical calculations.