To tackle the challenge of applying dynamic export cable in shallow water, this paper presents a study on the dynamic characteristic and fatigue performance of a dynamic cable with multi-wave configuration in a semi-sub floating offshore wind turbine (FOWT). The feasibility of a multi-wave configuration was validated. Through the comparative study on two hang-off positions on the FOWT, results showed in extreme sea states the configuration favored a higher hang-off point at the deck box, while the fatigue estimation revealed a lower position of hang-off provided superior performance. Finally, suggestions on the design and analysis of multi-wave cable configuration were given.
In 2021, floating wind technology is stepping into a more commercial phrase than it is ten years ago. A few more floating demonstrators have been installed on-site this year, such as the China Three Gorges (CTG) Demo (2021), the TetraSpar Demo by Stiesdal (2021), and the DemoSATH by Saitec (2021), etc. Following the increasing demands of floating offshore wind turbine (FOWT) worldwide, dynamic export power cables are employed in various water depths. To tackle the inevitable challenge of export cable design of FOWT in shallow water, the multi-wave configuration is considered a useful solution from the experience of the oil and gas industry (Hanonge, 2010).
Field experience on the dynamic export cable coupling to FOWT is rather insufficient over the years (Catapult, 2015). However, the limited relevant studies and researches mainly focus on several aspects, such as the parametric and sensitivity analysis on hydrostatic performance (Rentschler, 2020; Thies, 2017), the dynamic behaviors induced by the FOWT motions (Thies, 2012), the configuration optimization via various algorithms (Poirette, 2017; Rentschler, 2019), and the fatigue performance of cables (Sobhaniasl, 2020). Nonetheless, these studies are solely aiming at catenary and lazy wave solutions. The potential multi-wave configuration remained to be investigated.
