Study on Ampacity Improvement of ± 500 kV HVDC Submarine Cable Under Land Laying Environment

Submarine cables are an important component of offshore wind power, and its ampacity is directly proportional to power efficiency. The temperature of the submarine cable rises after landing due to unfavorable thermal conditions, which causes the land part of the submarine cable to become a bottleneck in ampacity. To address this bottleneck, this work uses FEM to create the ±500kV DC submarine cable in a land laying environment. Firstly, the better backfill material for the cable trenches is studied by comparing the heat transfer effect of different materials. On this basis, the effect of equipping a cooling circulating water system for further heat dissipation is analyzed, and tube parameters are designed. To validate the above scheme, this paper finally compares the ampacity of this scheme and direct burial under different working conditions. Results show that the scheme can improve the ampacity by about 54.1% at ordinary temperature. Therefore, the scheme in this paper can effectively improve the bottleneck of submarine cables in the land and provide guidance for improving the ampacity.