Impact of Untransposed Power Lines

Abstract

-Keywords -current sequence of three-phase system, flat phase arrangement, mutual impedances, self impedances, untransposed power line.

Adverse Peculiarity Arising with Overhead Power Lines

“…To make the calculation plausible, it is necessary to unscramble all the components of the expressions (2) referring to the sections 2 and 8 of [8], where zd = 0.148 + 0.7227i; zs = 0.05 + 0.3422; zf = 0.05 + 0.2987i.…”

“…In [8], it is shown that a power line becomes balanced if all mutual impedances are equal. If in flat arrangement of phases, the mutual inductance between two outside phases were equal to that between adjacent phases, then the power line would become balanced.…”

“…When a transformer is not ideal, on a par with mutual inductance the extra inductance in each of two phases appears. On the basis of [8], it can be said that an extra phase-to-phase capacitance would not play a significant role.…”

“…It requires a special power-line support. Besides, as it is shown in [8], some types of relay protection can be implemented better without transposition.…”

“…In [8], it is shown that voltage at the end of an untransposed power line can be balanced by a non-symmetrical load. The practical possibility of this measure will be investigated further by appropriate calculations.…”