Calculation of current carrying capacity of high-voltage AC submarine cables under different seabed conditions
Abstract
As offshore wind power development enters a new phase characterised by the parallel advancement of technological refinement, cost optimisation and expansion into diverse scenarios, submarine cables—as critical infrastructure for long-distance power transmission—exert a decisive influence on system safety and economic efficiency through their operational performance. Among these factors, current- carrying capacity, as the core parameter characterising a cable’s power transmission capability, is directly linked to equipment utilization and operational reliability. However, in complex subsea environments, high-voltage AC submarine cables still face critical challenges, including significant losses, marked variations in heat dissipation conditions across different sections, insufficient accuracy in current- carrying capacity calculation and monitoring, and prominent constraints in engineering implementation and operation and maintenance. To address these challenges, this paper utilises the COMSOL multi-physics finite element analysis platform and MATLAB numerical calculation tools to construct an electro-thermal coupling analysis model for high-voltage AC submarine cables. This enables the visualisation of current-carrying capacity and temperature fields, whilst systematically revealing their underlying mathematical correlation mechanisms. Building on this, comparative studies were conducted for two typical subsea installation methods—buried and laid—to analyse the influence of different subsea scenarios on the cable’s thermal conduction characteristics and current-carrying capacity. The results indicate that variations in the subsea environment significantly affect the current-carrying capacity of high-voltage AC submarine cables, with the laid method offering superior heat dissipation conditions compared to the buried method, thereby providing a higher current-carrying capacity. The findings of this study provide theoretical support for the safe and stable operation of submarine cables and offer significant reference value for optimising engineering design, controlling costs and improving power grid operational efficiency.