With the development of high voltage and ultra-high voltage applications in power system, the single-core XLPE cables are usually used instead of three-core cables.

Underground power cable system design presents unique design and installation challenges not found in the overhead transmission lines. Poorer thermal dissipation, confined spaces, lack of visibility, more difficult fault diagnosis, circulating earth currents, and frequent joints in an unfriendly environment are all problems that cable engineering design must overcome to deliver a reliable long term installation.