Maximizing Efficiency in Overhead Transmission Lines: A Critical Examination

In the context of constructing a typical new overhead transmission line (500kV, quad bundle, 225km length) in Australia, overlooking the importance of selecting the right conductor can have significant repercussions. In a terrain characterized by relatively flat landscapes and devoid of snow loads, opting for an inadequate conductor can lead to considerable line losses and wasted generation. Over a span of 50 years, these losses can amount to approximately 15% of the Net Present Value of the transmission line.

Moreover, the annual line losses stemming from a suboptimal choice of conductor, based on current generation mixes, range from 15 to 30 tons per kilometre of conductor—each year… year after year. This represents roughly 10% of the carbon footprint associated with the construction of such a line.

A notable example lies in comparing the traditional ACSR/GZ Orange conductors used half a century ago with the more efficient AAAC 1120 Selenium conductor available today. Transitioning to the latter can yield significant reductions in line losses, with further improvements achievable through the adoption of a compact AAAC 1120 design.

Furthermore, embracing advancements like High Temperature Low Sag conductors, equipped with fully annealed aluminum wires, presents options that need to be considered. While these conductors offer equivalent resistance to compact AAAC 1120 designs at the same diameter, they boast higher strength and are capable of operating at elevated temperatures. Although this entails greater line losses under high-temperature conditions and necessitates increased quantities of steel and foundations, along with higher costs for appropriately sized substations and ancillary equipment, it substantially mitigates the risk of supply disruptions.  The financial and risk balance is more aligned with short, congested sections and are much harder to justify for longer lines.

For a deeper understanding of the technical nuances surrounding overhead lines and comprehensive insights into life cycle analysis, consider enrolling in the specialized courses offered by mjlee consult. To explore further, please visit our website at www.mjleeconsult.com.au