Underground Transmission – Program 36

Program Overview
Program Description

There are a number of challenges in underground transmission (UT). Utilities need a better understanding of the condition of an aging UT infrastructure, which in many cases has exceeded its 40-year life expectancy, to strengthen existing cable systems and help asset managers with difficult upgrade and replacement decisions. Increased system robustness, higher capacity and longer life will require development and use of newer polymer insulations at extra-high-voltage (EHV) levels with integrated sensors. An ability to exploit the dynamic overload capacity of buried power cables promises better asset utilization at marginal extra cost. Transmission systems must deliver high power quality for the digital society, ideally immune from weather
extremes and in many cases serving urban centers with limited space for infrastructure expansion. To meet these needs the industry must accommodate increased application of buried power cables with greater power throughput, which places great importance on orderly replacements of mature cables with care that new advanced systems are at least as reliable. Transmission owners need guidance on safe and more efficient use of new materials, equipment, and construction methods for UT systems to boost economic productivity and prosperity. Also needed are advanced design tools to increase the effectiveness engineering resources, as well as to aid technology transfer to new knowledge workers. Efficient use of component materials, with lower losses, less construction impact, easier replacement and high recycle value, would benefit the environment and increase sustainability for generations.

EPRI’s Underground Transmission program is made up of three research areas; design, reliability and performance, increasing power flow and superconductivity. This research leads in the exploration and deployment of promising new technologies and tools to help UT owners design and operate cost-effective cable systems with increased power capacity and longer lives, diagnose problems before outages occur, and repair them at minimum cost and within acceptable time periods