Natural Modes of Power Line Carrier on Horizontal Three-Phase Lines

Formulas are developed for natural-mode parameters of a horizontal 3-phase transmission line. A method involving elementary algebra is described and paralleled by corresponding equivalents of matrix eigenvalue analysis. A numerical example is presented of calculating high-frequency natural-mode impedances and current or voltage components of an EHV (extra-high-voltage) line. The application of natural-mode analysis to the solution of some plc (power line carrier) problems is also illustrated.