Abstract A novel opto-mechanical platform to measure the dynamic response of a multi-megawatt wind turbine is developed and applied. This opto-mechanical platform measures the blade shape, blade deflections and characteristics of blade vibrations by tracking blade during operation without need for any modification or attachment to the turbine. Simultaneous measurements of the wind speed, wind direction, and turbulence intensity are made with a LiDAR scanning system. It is shown that there is an azimuthal variation of wind speed (that is major loads), turbulence (that is minor loads) during a rotor revolution which consequently leads to azimuthal variations of the blade’s vibration and fatigue loads during a rotor revolution. Measurements show a 4% higher level of blade vibrations in the top-most position compared to the bottom-most position. A maximum deflection of 6.5% of the blade length at the top-most position is measured. Measurements and BEM analysis show that loading on the blade at the bottom-most position contributes 30% more to the blade’s fatigue life (the number of cycles to failure at measured loading conditions) compared to the blade loading at the top-most position. These findings show that the opto-mechanical platform can be used to develop more accurate predictions of fatigue lifetime.

中文翻译：

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多兆瓦风力涡轮机动态响应的光学测量

摘要 开发并应用了一种用于测量多兆瓦级风力发电机动态响应的新型光机平台。该光机平台通过在运行期间跟踪叶片来测量叶片形状、叶片偏转和叶片振动特性，无需对涡轮机进行任何修改或连接。使用激光雷达扫描系统同时测量风速、风向和湍流强度。结果表明，转子旋转过程中存在风速（即主要载荷）、湍流（即较小载荷）的方位角变化，从而导致转子旋转过程中叶片振动和疲劳载荷的方位角变化。测量显示，与最底部位置相比，最顶部位置的叶片振动水平高出 4%。测量到最高位置处叶片长度的 6.5% 的最大偏转。测量和边界元分析表明，与最顶部位置的叶片载荷相比，最底部位置叶片上的载荷对叶片疲劳寿命（在测量的载荷条件下失效的循环次数）的贡献多 30%。这些发现表明，光机械平台可用于开发更准确的疲劳寿命预测。