Approximate computation of high-frequency characteristics for power line with horizontal disposition and middle-phase to ground coupling

Paper presents an approximate computation of high-frequency high-voltage power-line characteristics: amplitude, phase and group delay characteristic. Analytical approximate formulae are derived for the power line with three conductors in horizontal disposition and middle-phase to ground coupling. Expressions derived from modal analysis and detailed computation methods allow analysis of power-line high-frequency characteristics, like oscillations in high-frequency characteristics due to reflection on the power line. Such formulae are available in the literature for modal propagation functions and power-line amplitude characteristic. However, this paper also treats power-line phase characteristic and group delay important for digital communication systems design that are not thoroughly investigated in analog communications. The paper shows that nonlinearities in the phase characteristic due to reflection are determined with Hilbert transform of the amplitude characteristic. © 2003 Elsevier B.V. All rights reserved.