Electromagnetic interference from transmission lines.

摘要

he research in this thesis relates mainly to the following two topics: (1) modeling of random sources and random electromagnetic fields; (2) electromagnetic wave propagation and wave scattering from wires. For the first topic of the thesis, a new and rigorous model for predicting electromagnetic interference from corona on transmission lines is developed. In the model a general random source is considered for corona (as a random process with a random current and a random position on a conductor) and valid solutions for "Sommerfeld" integrals are used to calculate the electric and magnetic fields. The model is valid over a very wide range of frequencies and for field points at an unrestricted distance and direction from a transmission line. For the second topic of the thesis, approximate solutions for the spatial Fourier transforms (in the axial direction) of Sommerfeld-type integrals for the axial and vertical electric fields from a current on a thin wire of infinite length above a lossy earth are developed. The solutions are valid over a wide band of frequencies (1Hz-1GHz) and for distances from field points to the transmission line which are essentially unrestricted, as well as for a wide range of values of the Fourier transform variable,