Integral SHM-System for Offshore Wind Turbines Using Smart Wireless Sensors
Integral SHM-System for Offshore Wind Turbines Using Smart Wireless Sensors
复制标题
使用智能无线传感器的海上风力发电机整体 SHM 系统
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. Lynch
中科院分区：
文献类型：
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作者：
R. Rolfes;S. Zerbst;G. Haake;J. Lynch
目前，风力涡轮机每年会发生五次不可预见的损坏。特别是在恶劣天气下，位于海上的风力涡轮机很难进行目视检查。因此，涡轮机长时间停滞不前会导致经济效率低下，从而破坏该技术的长期可行性。因此，应持续监测承载结构，以尽量减少维护和维修的总成本。最终的结果是，涡轮机的使用寿命更长，经济可行性更高。为此目的，目前正在为风力涡轮机开发一种用于早期损伤检测和损伤定位的自动监测系统。现有的结构整体损伤检测技术大多采用频域方法。频移和模态振型变化通常用于大型结构（如桥梁、大型建筑和塔楼）的损伤检测。损伤可以引起结构刚度分布的变化，这必须通过使用自然激励测量动态响应来检测。尽管模态振型比频移对损伤更敏感，但使用模态振型需要安装大量传感器，以便可靠地检测模态振型变化，从而进行早期损伤检测[2]。我们开发的结构健康监测（SHM）系统的设计基于三个功能模块，这些模块可以跟踪涡轮塔和叶片元件的整体动态行为变化。该方法的一个关键特点是需要最少数量的应变计和加速度计来记录结构的状况。模块1分析最大应力与最大速度的比例关系；已经可以检测到部件刚度的微小变化。然后，启动模块3，对损伤进行定位和量化。模块3的方法是基于一个解决多参数特征值问题的数值模型。作为先决条件，需要高度分辨的特征频率和有效结构模型的参数化。模块2为未损坏的结构提供了这两种结构
Currently, wind turbines can incur unforeseen damage up to five times a year. Particularly during bad weather, wind turbines located offshore are difficult to access for visual inspection. As a result, long periods of turbine standstill can result in great economic inefficiencies that undermine the long-term viability of the technology. Hence, the load carrying structure should be monitored continuously in order to minimize the overall cost of maintenance and repair. The end result are turbines defined by extend lifetimes and greater economic viability. For that purpose, an automated monitoring system for early damage detection and damage localisation is currently under development for wind turbines. Most of the techniques existing for global damage detection of structures work by using frequency domain methods. Frequency shifts and mode shape changes are usually used for damage detection of large structures (e.g. bridges, large buildings and towers) [1]. Damage can cause a change in the distribution of structural stiffness which has to be detected by measuring dynamic responses using natural excitation. Even though mode shapes are more sensitive to damage compared to frequency shifts, the use of mode shapes requires a lot of sensors installed so as to reliably detect mode shape changes for early damage detection [2]. The design of our developed structural health monitoring (SHM) system is based on three functional modules that track changes in the global dynamic behaviour of both the turbine tower and blade elements. A key feature of the approach is the need for a minimal number of strain gages and accelerometers necessary to record the structure’s condition. Module 1 analyzes the proportionality of maximum stress and maximum velocity; already small changes in component stiffness can be detected. Afterwards, module 3 is activated for localization and quantization of the damage. The approach of module 3 is based on a numerical model which solves a multi-parameter eigenvalue problem. As a prerequisite, highly resolved eigenfrequencies and a parameterization of a validated structural model are required. Both are provided for the undamaged structure by module 2