Prospects for novel deformation processed Al/Ca composite conductors for overhead high voltage direct current (HVDC) power transmission

• We developed a novel deformation processed Al/Ca composite conductor.
• The Al/Ca composites were produced by powder metallurgy and severe plastic deformation.
• The Al/Ca composite conductor is lighter, stronger and more conductive than previous conductors.
• The elevated temperature performance of the composite was improved by Al2Ca intermetallics.
• Al/Ca composite conductor is economically efficient for high voltage power transmission.

In the quest for more efficient long-distance power transmission, High Voltage Direct Current (HVDC) transmission offers a reliable, cost-effective alternative to HVAC for long distance overhead transmission. Development of stronger, more conductive, and lighter conductor materials could lower HVDC construction costs, reduce energy losses, and increase reliability. In this paper, we describe a new deformation processed Al/Ca composite conductor now in development that has the potential to offer substantially lower density, higher strength, and higher conductivity for HVDC than today's conductor materials. This Al/Ca composite has shown promising early corrosion and elevated temperature performance test results, but additional research is needed to determine its fatigue and creep strengths, as well as its susceptibility to electrotransport phenomena and other factors. The design process, production methods, and physical properties of the new composite conductor are discussed. An economic and thermal analysis of this conductor material is also presented.