A Review of the Developments in Capacity-Uprating Conductors for Overhead Transmission Lines

Globally escalating electricity demand necessitates substantial power grid capacity expansion. Current transmission line capacity enhancement technologies are seriously constrained by factors including limited accuracy of computational models, elevated line losses, requirements for new line construction, and substantial capital investment. Capacity-uprating conductors, recognized for their superior current-carrying performance and cost-effective retrofitting, represent one of the most viable solutions for transmission augmentation. However, their large-scale deployment remains impeded by increased line losses and high costs. This review systematically analyses critical constraints on transmission line ampacity through computational modeling and elucidates conductor heat dissipation pathways. Based on this foundation, we synthesize recent advancements in capacity-uprating conductors across three key dimensions: structural optimization, material engineering, and passive radiative cooling technologies. We concurrently evaluate their applications in power transmission projects and explore promising future development directions. This review aims to provide a theoretical foundation, guiding next-generation capacity enhancement solutions for grid modernization.