风机中心布置的Y形和偏心布置的Δ(Delta)形半潜式平台是深远海半潜式风机的主流平台形式，但其动力特性差异缺乏系统量化对比的相关研究。该文以最小化系统成本和累积疲劳损伤为目标，以平台及系泊关键主尺寸为变量，优化设计了适配DTU 10-MW风机的中心布置和偏心布置的半潜式平台及系泊方案；采用风浪联合的缩尺模型试验方法，针对风机的额定作业和极限自存的典型工况，测试了2类半潜式风机在风单独作用、波浪单独作用以及风浪联合作用下的动力响应；通过在时频域内对关键动力特性(平台运动、机舱加速度、塔基弯矩和系泊导缆孔张力)的统计分析，揭示了环境荷载作用效应及其耦合特性。结果表明，Δ形半潜式风机存在垂荡和纵摇的耦合效应，纵摇会放大偏心风机的垂向运动；针对机舱加速度和塔基弯矩，Y形半潜式风机在长波浪周期极端工况下更大，Δ形半潜式风机在小波浪周期作业工况下更大。将该研究获得的典型工况动力特性与全寿命周期海况相结合进行分析，可为深远海浮式风电平台选型设计提供量化评价依据。

Objective: Harnessing high-quality deep-sea wind energy, semi-submersible wind turbines have emerged as a prevalent structural solution in the offshore wind energy industry. In particular, the Y-shaped semi-submersible platform, featuring a centrally arranged wind turbine, and the Δ-shaped semi-submersible platform, with an eccentrically arranged wind turbine, are two dominant configurations for deep-sea applications. However, the systematic quantification of their dynamic characteristic disparities remains lacking, which can be attributed to various factors, such as incomplete numerical methodologies, variations in turbine power capacities, divergent design standards, and construction techniques among existing prototypes, as well as potential technical and commercial confidentiality constraints. Methods: To facilitate an equitable comparison, the optimized design of centrally and eccentrically arranged semi-submersible platforms and mooring systems suitable for the DTU 10-MW wind turbine is obtained, with minimizing the system costs and cumulative fatigue damage as the objectives and the main dimensions of the platform and mooring as the key variables. Subsequently, semi-submersible wind turbine test models with a scale ratio of 1∶70 were designed and established based on the similarity criterion. Dynamic characteristic testing was conducted using scaled model tests under combined wind and wave conditions, focusing on the rated operation and extreme survival mode of the wind turbines. A comparative analysis was conducted to assess the effects of wind-only, wave-only, and combined wind-wave conditions on dynamic responses of the two semi-submersible wind turbines. Through statistical analysis of the time and frequency domains of key dynamic performance indicators, such as platform motion, nacelle acceleration, tower base bending moment, and mooring fairlead tension, the effect of different loads, the coupling characteristics among various dynamic responses, and the excitation mechanisms were investigated. Results: The results indicate that the pitch natural periods of the two semi-submersible wind turbines are similar. The larger vertical static water stiffness of the Y-shaped semi-submersible wind turbine results in a shorter heave natural period. The Δ-shaped semi-submersible platform's four-line mooring system demonstrates greater structural stiffness over the Y-shaped semi-submersible platform's three-line system, resulting in a reduced surge natural period. The eccentric arrangement of the Δ-shaped semi-submersible wind turbine is prone to the coupling effects of the heave and pitch; the pitch amplifies the vertical motion of the wind turbine. The difference in mooring stiffness caused by different mooring schemes leads to a significantly smaller surge response and marginally smaller pitch response in the Δ-shaped semi-submersible wind turbine compared with that in the Y-shaped one. Nacelle accelerations and tower base bending moments are more pronounced in the Y-shaped semi-submersible wind turbine under long-period extreme waves, whereas the Δ-shaped semisubmersible wind turbine exhibits higher responses under short-period operational waves. Nonlinear mooring system behavior driven by load-induced equilibrium shifts causes upstream lines to enter a tensioned, nonlinear stiffness regime under combined wind-wave loading, exacerbating fairlead tension fluctuations and spectral peak magnitudes. Conclusions: This study highlights the necessity of accounting for the dynamic characteristic differences between Y-shaped and Δ-shaped semi-submersible wind turbines for various sea states and limit states during engineering design. Furthermore, by integrating the dynamic characteristics observed in typical working conditions with full-lifecycle sea condition data, this research provides a quantitative framework for the selection and design optimization of deep-sea floating wind turbine platforms.