Summary

Renewable and distributed power generation is displacing conventional base load coal and nuclear plants. This often causes large shifts in power flow during both normal and emergency operation of the transmission system. As a result, certain existing AC overhead transmission lines may exceed their design thermal rating during either normal or emergency operation.

This brochure concerns methods of increasing the thermal rating of existing overhead lines by raising the maximum temperature of the original conductor or re-conductoring the line with larger or high-temperature, low-sag conductors while avoiding the replacement or extensive reinforcement of existing transmission structures. In most applications, the line structures must be in good or excellent condition, to use these uprating methods. The existing phase conductors, however, may be replaced with High-Temperature, Low-Sag (HTLS) conductors.

If the existing line voltage is to be increased (Voltage Upgrading), other CIGRE brochures should be consulted.

Additional informations

Publication type Technical Brochures
Reference 763
Publication year 2019
Publisher CIGRE
Study committees Overhead lines (B2)
Working groups WG B2.55
File size 8 MB
Pages number 104
Price for non member 200 €
Price for member Free

Keywords

overhead lines

Conductors for the uprating of existing overhead lines
Conductors for the uprating of existing overhead lines