Worldwide underground transmission cable practices

Underground transmission cables are a vital part of any power transmission system which means that the selection of a particular cable must be based upon many considerations ranging from the cost of losses to environmental concerns. The focus of this paper is on the design, selection, and testing of transmission cables within specific geographic regions. Design considerations on a regional basis includes temperature constraints, voltage and voltage stress limits, capacity and ampacity, backfill requirements, cooling and bonding. The material presented in this paper covers land based transmission cables only. Submarine cables, URD or UD cables are not included.