基於模態特徵之風力機監測可行性研究：以一林口風力機為例

風力機於再生能源扮演重要之角色，目前臺灣已規劃大面積之風力發電場域，然而日後建置、運作、維護必須仰賴監測之手段，確保風場內之風力機的運轉及安全符合規範要求及設計性能。因此，本研究基於現地長期量測技術，建立一套風力機監測手段，並探討該方法之可行性。於本研究中，首先針對風力機動態量測反應（如風力機不同高程之絕對加速度反應），萃取風力機相關模態特徵，包含自然頻率、模態振形，並持續追蹤該模態特徵的變化，以及與風力機轉速、風速間之關係。另外，本研究利用風力機簡化數值模型，比對經由量測反應獲得之模態特徵，並藉由該模型當風力機耐久性構材劣化時，如表面構材遭受腐蝕效應時，探討模態特徵相應之改變與特性，可做為未來風力機監測之觀察重點，以及判斷劣化程度之指標。由本研究之成果可見，風力機的低頻率模態具有一定程度之穩定性，較高頻率之模態會受風速與轉速影響較大，而觀察前幾個模態之模態振形變化，可了解風力機受腐蝕影響之程度。

關鍵字

風力機；結構健康監測；系統識別；模態分析

並列摘要

Wind turbines play an important role in renewable energy. Taiwan has now planned a large area as an offshore wind farm for these wind turbines. However, the construction, operation, and maintenance of these wind turbines still need to rely on structural health monitoring methods to ensure the functionality of these turbines as well as to retain the required performance specified in the design code. Therefore, based on the on-site long-term instrumentation, this study investigates the feasibility of implementing structural health monitoring strategies for a specific wind turbine in Linkou. In this study, the dynamic responses (i.e., absolute accelerations at different elevations of the wind turbine) are firstly employed to extract the modal properties, including the natural frequencies and mode shapes. The changes of these modal characteristics are continuously tracked, while the relationships of the modal properties with respect to the turbine angular speed and wind speed are also explored. In addition, this study exploits a simplified numerical model of the wind turbine to compare the modal characteristics extracted from the in-situ measurements. This model is also employed to investigate the changes of the corresponding modal characteristics when the durability materials of this wind turbine are deteriorated, e.g., when the surface of the support structure suffers from corrosion effects. These changes in modal characteristics can be used as an indicator that informs the current conditions of the wind turbine. As found in the results, the low frequency modes can be continuously extracted and more trackable. The high frequency modes can vary with respect to the turbine angular speed and wind speed. Moreover, the extent to which the wind turbine is affected by corrosion can be observed from the changes of modal properties in the first few modes.

並列關鍵字

wind turbine ； structural health monitoring ； system identification ； modal analysis

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