Simulation and Analysis of Submarine Cable Based on Electro-Thermal-Flow Multi-physics Coupling

Submarine cable power transmission is almost the only option for off shore wind farms, island nuclear power plants and other cross sea projects, so studying the operation status of submarine cables is of great significance for cross-sea power transmission projects. As the submarine cable is set on the seabed, it is complex to directly study its operation state, and it can be easily studied by using simulation software.In this paper, a two-dimensional (2D) model of the 160 kV submarine cables and its laying environment are set up by using the COMSOL software, and the operating state of the submarine cable is analysed by means of electro-thermal-flow multiphysics coupling.The results show that under buried conditions, the temperature of the surrounding soil will rise greatly, and the temperature will increase by about 20°C; when the current was greater than about 900A, with the increase of current the electric field strength of the insulation layer is reversed inside and outside. But the electric field strength in the center of the insulation layer remains basically unchanged when the current changes, maintaining it at 9. 97kV/mm; The velocity of seawater has a great influence on the ampacity, but it is mainly concentrated in the low velocity section, and when the velocity of seawater is greater than 0.02 m/s, the ampacity basically remains unchanged.