Requirements for different components in cables for offshore application

The installation of offshore wind-farms and the increase in electricity trading between countries has resulted in an increased number of offshore submarine cable installations as an efficient way to solve many electricity supply issues. Although offshore cables with XLPE insulation are similar to land based cables, the offshore environment adds to the challenges of very long lengths, much more onerous installation conditions and an aggressive environment. This paper discusses how these issues are confronted in distribution cable designs. In addition, the necessities for long-lasting medium voltage cables up to the lower high voltage level in wet conditions plus the increase in performance needs are discussed. It also covers the different requirements of 3 core installation and water tree retardency tests in sea water applications. This paper will focus on medium and high voltage cables as they are used extensively for offshore applications connecting wind farms, for lake crossings and for inter-island connections.