Multi-Physics Simulation Study on Current Carrying Characteristics of High Voltage AC Submarine Cable Under Multiple Working Conditions

The submarine cable links offshore wind power and land power equipment. The most efficient way to convey electricity will be achieved if the cable's current carrying capacity can be precisely determined. This paper examines the electromagnetic-thermal field of a 500kV AC submarine cable under both normal and abnormal operating conditions using Comsol finite element simulation software. The findings demonstrate that, in steady state conditions, there is a significant temperature difference inside the cable. The buried depth of it and the upper boundary temperature of soil are inversely proportional to the carrying capacity. Soil thermal conductivity is proportional to carrying capacity. Under abnormal conditions, transient overvoltage will cause its temperature to rise rapidly. The breakdown of the main insulation will destroy the insulation layer. Besides, the large current generated will cause the temperature inside it to rise. The temperature of the submarine cable will somewhat increase if metal sheath and armor layer are grounded abnormally, but this will not interfere with the submarine cable's ability to function normally.