Performance Evaluation of Dynamic HV Cables With Al Conductors for Floating Offshore Wind Turbines

Abstract

Floating Offshore Wind turbine installations will require HV dynamic power cables to be connected to the of longer length static export power cables. Experience from offshore wind installations has highlighted the criticality of power cables, underlining the need for high integrity, yet cost effective cable solutions. This paper will assess the mechanical performance and load parameters for an Aluminum power conductor cable. Whilst copper is the conventional choice due to its lower resistive losses, Aluminum cores are increasingly used for static power cables, due to their benefits regarding overall cable weight and material cost. The work presented adopts a coupled aero-elastic and hydrodynamic modelling approach to simulate the behavior of the well-documented OC4 semi-sub platform, together with the 5MW NREL wind turbine. The model allows a direct comparison between the two cable types, maintaining the overall system and environmental conditions. The results inform the design envelope regarding the ultimate load conditions a for the two principle cable designs, providing global load estimates, such as effective tension and bending stresses, to inform the local stress analysis. Furthermore, the results will form the basis for future physical demonstration and validation tests. This paper will be of interest to technology developers and practitioners concerned with submarine dynamic power cables, offer a methodology to directly compare and evaluate different cable design options, and providing some design guidance for and aluminum conductor cables.