Analysis of the influence of ambient conditions on the ampacity of Kevlar-armoured subsea power cables

This paper presents the electro-thermal modelling and simulation, done on a standard Kevlar-armored subsea electrooptic cable based on the finite element analysis (FEA) approach, to determine the cable ampacity when operated in air, water and buried in the seabed under the relevant ambient environmental conditions. Compared to the ampacity in air at 30 ºC, the ampacities in air, water with no flow condition and seabed buried conditions with a thermal conductivity of 0.8 W/m-k could be 1.37 times, 1.57 times and 1.5 times, respectively, at an ambient temperature of 5 ºC; and the same could be 1.13 and 1.36 and 1.31 times, respectively, at 20 ºC. Under the influence of convective ambient flow fields, the ampacities could be increased only up to a maximum of 9% and 3%, with air and water flows of 20 m/s and 5 m/s, respectively. The results serve as a guideline for determining the cable ampacities for various environmental applications, based on the available cable current rating under specified ambient operating conditions.