The Spatial Distribution of Electric Field as a Unifying Idea in Transmission Line Design

It is shown that the most important electrical design criteria for long (i.e., stability limited) high voltage overhead transmission lines operating at a given voltage are all related to the spatial electric field distribution between phase conductors. Hence, when designing a long transmission line, a change in one design parameter necessarily causes changes in the others. It is shown how an understanding of these relationships can lead to insight into the design and to the tradeoffs that must be made in designing these transmission lines. More specifically, a more spatially uniform electric field implies an increased power capacity for long transmission lines but also reduces the critical flashover voltage and increases the capacitance per unit length.