Transmission line with asymmetrical phase arrangement

摘要

A factor affecting of electrical energy over a set of three-phase transmission line is the degree of unbalance produced by asymmetrical placement of line conductors above the ground plane. This unbalanced condition leads to generation of negative - and zero-sequence voltage and currents which may have adverse effects sufficient to require line transposition. Generators, motors, shunt reactors, and also relay performances may be affected by these negative- and -zero-sequence values. The object of this study will be to examine the unbalance condition, both electrostatically and electromagnetically, for selected Hungarian - high voltage (400kV) - single circuit lines and foreign double circuit example lines (because the complexity of double circuit calculations), to obtain a quantitative view of the importance of these factors. In Hungary never been made this type of theoretical deduction before, so it can help for the students and engineers to understand these factors. This may indicate what degree of transposition - if any - is required to meet design criteria.