Analysis of Thermal Field Distribution Characteristics of Different Structure Submarine Cables in Diverse Laying Environments

It is essential to calculate the temperature of conductors according to the temperature of optical fibers in submarine cable for monitoring the temperature of conductors and calculating current-carrying capacity. The finite element model of photoelectric composite submarine cable based on Comsol is established. The thermal field distribution characteristics of oil-filled submarine cable, three-core Cross-linked polyethene (XLPE) submarine cable and single-core XLPE submarine cable in different laying environments including landing section, intertidal zone, seawater and seabed were simulated, the relationship between the temperature values of each part of the submarine cable and the optical fiber in different laying environments was analyzed and studied, so as to obtain the temperature values of each structure inside the submarine cable. The temperature distribution of oil-filled submarine cable, three-core XLPE submarine cable and single-core XLPE submarine cable under typical faults is analyzed. The temperature of the optical fiber is affected by the position, and the temperature of the submarine cable gradually decreases from inside to outside. There is a linear relationship between the temperature of the optical fiber and the conductor core. The expressions of the temperature of the conductor, the outer insulation layer, the outer sheath of the cable and the optical fiber are also established, providing a theoretical basis for temperature monitoring of the submarine cable conductor and calculation of the current carrying capacity.