Finite element modelling of dynamic power cable for marine renewable installations

Abstract

The purpose of this study is to analyze and further develop a marine power cable by combining mechanical, electrical, and thermal simulations with previous experimental data from a tested cable. The project is based on an existing cable that has been subjected to tensile, bending, torsion, and fatigue testing at the Department of Mechanics and Maritime Sciences at Chalmers University of Technology. By digitally modelling the cable’s cross-section and lay length in CAD software (Fusion 360) and conducting finite element simulations in ANSYS Workbench, the behavior of the cable under various loading conditions can be analyzed with high accuracy. A central objective is to investigate how to replicate an experiment to a digital analysis by using FEA, particularly in bending and tension. In parallel, the study also includes an analysis of the cable's electrical and thermal behavior, focusing on how heat is generated in the conductor and transferred through the insulation layers with a simplified cable model. This is being done to provide a comprehensive understanding of the cable’s performance under realistic operational conditions with a simpler model without the need for extensive computer power that is not available for the average person. Because fiber-based conductor materials, such as helically winded copper wires, lead to nonlinear models that are computationally heavy, the study purposefully includes calculations of effective material properties and analysis of different moments of inertias. This allows simplification of geometry by modelling fiber bundles as solid bodies with equivalent mechanical behavior, significantly reducing simulation time without sacrificing accuracy. The goal is to compare the simulation results with previous experimental data to validate the model and use it as a foundation for improving the cable’s design in future studies. These improvements may include new material choices, modified geometry, or new combinations of structural layers. The overall objective is to develop a cable that can be stronger, lighter, and more reliable. Additionally, the cable should be easier to handle during maintenance and better suited for use in marine environments, both in terms of electrical efficiency and mechanical durability.