The design and financing of commercial-scale floating offshore wind projects require a better understanding of how power generation differs between newer floating turbines and well-established fixed-bottom turbines. In floating turbines, platform mobility causes additional rotor motion that can change the time-averaged power generation. In this work, OpenFAST simulations examine the power generated by the National Renewable Energy Laboratory's 5-MW reference turbine mounted on the OC3-UMaine spar and OC4-DeepCWind semisubmersible floating platforms, subjected to extreme irregular waves and below-rated turbulent inflow wind from large-eddy simulations of a neutral atmospheric boundary layer. For these below-rated conditions, average power generation in floating turbines is most affected by two types of turbine displacements: an average rotor pitch angle that reduces power, caused by platform pitch; and rotor motion upwind-downwind that increases power, caused by platform surge and pitch. The relative balance between these two effects determines whether a floating platform causes power gains or losses compared to a fixed-bottom turbine; for example, the spar creates modest (3.1%–4.5%) power gains, whereas the semisubmersible creates insignificant (0.1%–0.2%) power gains for the simulated conditions. Furthermore, platform surge and pitch motions must be analyzed concurrently to fully capture power generation in floating turbines, which is not yet universal practice. Finally, a simple analytical model for predicting average power in floating turbines under below-rated wind speeds is proposed, incorporating effects from both the time-averaged pitch displacement and the dynamic upwind-downwind displacements.

中文翻译：

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浮动平台对翼梁和半潜式风力涡轮机发电的影响

商业规模的浮动海上风电项目的设计和融资需要更好地了解新型浮动涡轮机和成熟的固定底部涡轮机之间的发电量有何不同。在浮动涡轮机中，平台移动性会导致额外的转子运动，从而改变时间平均发电量。在这项工作中，OpenFAST 模拟检查了安装在 OC3-UMaine spar 和 OC4-DeepCWind 半潜式浮动平台上的国家可再生能源实验室的 5 MW 参考涡轮机产生的功率，这些涡轮机受到极端不规则波浪和来自大型-中性大气边界层的涡流模拟。对于这些低于额定值的条件，浮动涡轮机的平均发电量受两种涡轮机排量的影响最大：由平台俯仰引起的降低功率的平均转子俯仰角；和转子运动逆风顺风增加功率，由平台喘振和俯仰引起。这两种效应之间的相对平衡决定了浮动平台与固定底部涡轮机相比是否会导致功率增益或损耗；例如，在模拟条件下，spar 产生适度的 (3.1%–4.5%) 功率增益，而半潜式可产生微不足道的 (0.1%–0.2%) 功率增益。此外，必须同时分析平台喘振和俯仰运动，以完全捕获浮动涡轮机的发电量，这还不是普遍做法。最后，提出了一种用于预测低于额定风速下浮动涡轮机平均功率的简单分析模型，