ABSTRACT
A new floating wind turbine concept, named as SJTU-SPIC, is developed and addressed in this study. It is composed of the DTU 10MW reference wind turbine and a newly designed Semi-submersible platform featured with three Partially Inclined side Columns. These three partially inclined side columns were introduced to achieve a good stability with a relatively small displacement. This study carried out an experimental study on the dynamic responses of the SJTU-SPIC concept considering a water depth of 60 m. The model test was conducted in the Deepwater Offshore Basin in Shanghai Jiao Tong University at a Froude scale of 1:64. Wind-only, wave-only and combined wind-wave cases were tested and analyzed under operational conditions. The effects of excitation loads were identified and dynamic responses of the semi-submersible wind turbine system in different environmental conditions were investigated.
Offshore floating wind turbines see significant advantages in wind resources, service time, construction scale and public acceptance (Liu et al., 2016). However, the development of the offshore wind industry is currently facing the challenges of high cost in the wind turbine fabrication, installation and transportation aspects (Willis et al., 2018). One of the most promising solutions is to achieve higher generating efficiency through upscaling the wind turbines from 5 MW, 8 MW to 10 MW and then 12 MW to harness more wind resources (Igwemezie et al.,2019). For example, the Technical University of Denmark (DTU) developed a 10 MW reference wind turbine (Bak et al, 2013) by upscaling the NREL 5MW wind turbine. The DTU 10MW wind turbine has been widely studied.
For a floating wind turbine concept with larger turbine size, the floating support platform usually has higher requirements on stability, structural integrity and dynamic behavior, especially in intermediate water owing to complex wind and wave conditions. The commonly studied supporting platforms for floating wind turbines consist of spar, TLP, semi-submersible and barge. Among them, TLP, semi-submersible and barge are feasible for intermediate water depth. The construction, installation, and commissioning of a semi-submersible wind turbine are more convenient and cost-effective than spar- and TLP-type wind turbines (Liu et al., 2016). In this study, a new concept of Semisubmersible platform with Partially Inclined Columns (SJTU-SPIC) was designed to support the DTU 10MW reference wind turbine. The platform features three partially-inclined side columns that can provide good stability performance with a relatively small displacement.
