Presentations

Abstract

As offshore wind energy expands into deeper waters, the design of offshore substations becomes a critical challenge, making floating solutions increasingly appealing and sometimes necessary. This work investigates the design of Station Keeping Systems (SKS) for a 500+ MW floating substation in intermediate to deep waters and the integration of six to ten Inter-Array Cables (IAC) plus two export cables, for a total of eight to twelve Dynamic Power Cables (DPCs). The substation is supported by a semi-submersible platform composed of two pontoons and four columns. Various configurations, from catenary to semi-taut, and different materials are investigated and compared to identify the best techno-economic SKS solutions. Key Performance Indicators (KPIs) such as maximum operational and extreme platform offset, platform declinations, and accelerations at the topside are used to evaluate the technical performances of the different solutions. Structural integrity of both SKS and DPCs is ensured in agreement with standards. Due to the large number of cables connected to the platform, co-design of the SKS and DPCs becomes relevant. Depending on the configuration, traditional decoupled analysis might fail to correctly capture the dynamics of the overall system. This investigation is primarily conducted via numerical simulations (both fully coupled and decoupled) using the software OrcaFlex. However, an experimental campaign in a wave tank, including both SKS and DPCs, is planned and will soon be executed. The results of the experimental campaign will serve in the future as a basis to validate the numerical models and the derived conclusions.