Insulated cable systems with high current ratings, case studies and practical applications

Current rating computations for HV and EHV insulated cables play a crucial role in the planning phase of a new undergrounded line for both an entirely cable link and a mixed or hybrid (cascade connection of overhead and cable line) one. The paper gives a wide overview of the technical solutions which allow very high current ratings in undergrounded insulated cables. These solutions are examined from a theoretical standpoint and practical applications are shown and explained. The paper demonstrates that in underground insulated cables current rating up to 2500 A can be reached.