Overhead Lines

Abstract

Results derived from electromagnetic transients simulations can be of vital importance for overhead line design. Two types of time-domain models have been developed for overhead lines: lumped-and distributed-parameter models. The selection of an adequate line model is required in many transient studies, it is probably in overvoltage calculations where adequate and accurate line models are crucial. Line matrices can be provided for the system of physical conductors, the system of equivalent phase conductors, or symmetrical components of the equivalent phase conductors. The concept of non-uniform line is used to deal with line geometries where the longitudinal variation of line parameters can be significant. Examples of this type of line are lines crossing rivers or entering substations. A model of the corona effect based on microscopic processes of the phenomenon is very complicated and impractical for transient analysis in transmission lines.