有別於固定式基礎離岸風機，浮式離岸風機（FOWTs）能夠在風能較多的地點設置，而不受水深限制。然而，由於風、浪和浮式離岸風機之間的動態相互作用，浮式離岸風機的分析和最佳化面臨挑戰。本研究建立了一個風浪耦合的半潛式浮動平台模型，其中風力分析使用OpenFAST軟體進行，波浪力分析則使用朱聖浩教授團隊開發的軟體進行，而塔架以及下部支撐結構則使用有限元素法的大變形分析。本研究旨在探討15 MW的半潛式平台浮式離岸風機，於100公尺水深時的最佳化設計。我們將重點聚焦於兩個主要方向：首先，研究風浪方向對最佳設計的影響，風與浪的方向設定為 -60°至60°，並模擬其在發電的環境條件；其次，將極端條件下的示性波高分成10、11、12公尺，探討示性波高與最佳設計結果之間的關係。最佳化過程中所使用的載重組合，採用國際電工委員會所編修的設計規範IEC 61400-3-1 [1]和IEC 61400-3-2 [2]。結果表明，當浮式離岸風機在發電狀態面臨不同風浪方向時，對設計結果的影響不大；隨著示性波高的增加，浮式離岸風機的設計用鋼量也會增加。當示性波高設定為12公尺時，塔架加上浮台的總用鋼量達到43000噸重。因此，可以得出結論，波浪力對浮式離岸風機的分析有顯著影響。此外，台灣處於亞熱帶地區，長年受颱風侵擾，浮式離岸風機在面臨如此極端條件下，穩定性與安全性的問題還需要進一步探討。本研究旨在提供浮式離岸風機的初步設計評估，考量成本以及目前的技術條件，台灣應以固定式離岸風機為主，尚不適合立即建置浮式離岸風電。
本研究所使用的電腦輔助分析程式由朱聖浩教授研究團隊所開發，分析程式與研究成果皆為公開資源。

Unlike fixed-bottom wind turbines, floating offshore wind turbines (FOWTs) are not constrained by the water depth, allowing for deploying wind turbines in more locations with higher wind speeds. However, the analysis and optimization of FOWTs present unique challenges due to the dynamic interactions between the wind, waves, and the FOWT. In this study, an aero-hydrodynamic coupled semi-submersible floating platform model is established, with the aerodynamic analysis conducted using the OpenFAST software, and the hydrodynamic analysis utilizing software developed by the team of Shen-Haw Ju. The tower and supporting structure of the FOWT are analyzed under large deformation using a finite element analysis program. This thesis aims to research the optimal design of 15 MW semi-submersible FOWT in 100 m water depth. The study focuses on two main directions: first, investigating whether the wind and wave directions impact the optimal design; second, exploring the relationship between the significant wave height (Hs) and the optimal design results. The optimization process is based on the design load cases in IEC 61400-3-1 [1] and IEC 61400-3-2 [2]. The results indicate that, the different wind and wave directions during the FOWT's power production state have minimal influence on the optimal design. Furthermore, as the Hs increases, there is a corresponding rise in the optimal steel weight. Thus, it can be concluded that hydrodynamics significantly influences the analysis of FOWTs. When the significant wave height is set to 12 m, the total steel weight of the tower plus the floating platform reaches 43,000 tons. Additionally, Taiwan is situated in a subtropical region and has been frequently affected by cyclones. Consequently, there is a need for further investigation of the stability and safety of the FOWTs under such extreme environmental conditions. The primary objective of this study is to provide an initial design evaluation of the FOWTs. However, considering the cost implications and current technical limitations, Taiwan should primarily concentrate on fixed OWTs. It is not suitable for the immediate construction of floating offshore wind power.
Note that the computer programs developed by the research team of Shen-Haw Ju are open and free to use.

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