Postolatii - Institute for Power Engineering, Moldova Academy of Science, Moscow Power Institut, BINOM researcch and tecnology firm, Republic of Moldova, Russia
Soldatov - Institute for Power Engineering, Moldova Academy of Science, Moscow Power Institut, BINOM researcch and tecnology firm, Republic of Moldova, Russia
Astakhov - Institute for Power Engineering, Moldova Academy of Science, Moscow Power Institut, BINOM researcch and tecnology firm, Republic of Moldova, Russia
Yarnffi - Institute for Power Engineering, Moldova Academy of Science, Moscow Power Institut, BINOM researcch and tecnology firm, Republic of Moldova, Russia

An approach to selection of variants, types and voltage classes of highvoltage transmission lines in the context of electric power system development is elaborated. Power systems formation proceeds in accordance with power consumption increase. During a service life of transmission lines their load becomes several times greater. In this connection the problem of construction of new lines with enhanced capability occurs. These can be the lines of higher voltage classes, modern lines with enhanced capability, multi-circuit and compensated lines. One of alternative approaches to the important problems concerned with providing an increase in power flows by modification of transmission lines.with the construction elements selected for a higher voltage class is examined in the present paper. The studies and analysis are applied to the high-voltage lines constructed at first as those of 220 kV single-circuit With,considerable phase splitting or as double-circuit lines later transformed into 500 kV single-circuit lines with phase construction and suspension points replaced, but with the supports, the number of conductors and their cross section area as well as the number of insulators maintained. The variants of 220 and 500 kV lines with optimal conductorto-phase and phase-to-support configuration which demonstrate enhanced capability compared with the variants of typical lines of the same voltage class are examined.