【摘要】：隨著社會經(jīng)濟的發(fā)展能源消耗以及污染問題的日漸嚴重,風能作為一種清潔能源受到全球各國政府的青睞。風力發(fā)電機葉片承載著旋轉的主要任務,其目的就是將風能轉換成電能。由于風力發(fā)電機組常常在一些偏遠、自然環(huán)境極其惡劣的條件下工作,并且葉片在高空中處于懸空的狀態(tài),一旦發(fā)生故障會給整個風電機組造成停機,嚴重影響到了風力發(fā)電機的發(fā)電效率。因此,開展風力發(fā)電機葉片故障的研究,對保證風力發(fā)電機的安全和長時間運行具有非常重要的意義。本文對風電葉片故障診斷的國內外研究現(xiàn)狀以及在生活中常見的風電葉片結構和制動進行了介紹,對葉片故障發(fā)生的主要原因、故障類型、故障產(chǎn)生的機理以及常用的故障監(jiān)測方法進行了對比研究。通過對葉片等效懸臂梁結構的動、靜頻公式進行了推導,對比數(shù)值分析和理論推導的求解結果,表明有限元的方法對葉片分析的有效性。利用Wilson葉片優(yōu)化方法,結合CATIA和Profili選型軟件,完成對葉片三維模型的建立。根據(jù)葉片損傷前后的模態(tài)應變能變化率,作為診斷葉片是否發(fā)生損傷的依據(jù);將模態(tài)應變能變化率和神經(jīng)網(wǎng)絡二者結合,該方法具有較高的辨識率、可準確的辨識葉片損傷。針對葉片可能存在的裂紋損傷進行不同方向、不同位置和不同深度的分析,通過引入葉片健康狀況的評價指標RMSD(均方值),建立RMSD與裂紋損傷區(qū)域面積S的關系,在一定程度上實現(xiàn)了葉片裂紋損傷的量化。驅動器在故障檢測中起著重要作用,而壓電驅動器類型和激勵頻率的選擇尤為重要,文中重點對驅動器的幾何尺寸以及泊松比對共振頻率的影響分析。分析結果表明利用有限元能夠有效的模擬出發(fā)生在葉片上的損傷區(qū)域,對風力發(fā)電機葉片故障發(fā)生關注區(qū)域的選擇提供了幫助,降低了人工勞動成本,提高故障發(fā)生的檢測率,具有一定的現(xiàn)實意義。對影響故障檢測的壓電驅動器共振頻率內、外部因素分析,這不僅僅為驅動器結構和激勵頻率的選擇提供了幫助,還為壓電驅動器的優(yōu)化設計提供了理論指導。
[Abstract]:With the development of social economy, energy consumption and pollution problem become more and more serious, wind energy as a clean energy is favored by governments all over the world. Wind turbine blades carry the main task of rotation, the purpose of which is to convert wind energy into electricity. Since wind turbines often work in remote, extremely harsh natural conditions, and the blades are in a suspended state at high altitude, once a failure occurs, the whole wind turbine will be shut down. The efficiency of wind power generation is seriously affected. Therefore, it is very important to study the blade faults of wind turbine to ensure the safety and long time operation of wind turbine. This paper introduces the status quo of wind turbine blade fault diagnosis at home and abroad, and introduces the structure and braking of wind turbine blade, the main cause and type of blade fault. The mechanism of fault generation and common fault monitoring methods are compared. Through the derivation of the dynamic and static frequency formula of the equivalent cantilever beam structure, the results of numerical analysis and theoretical derivation show that the finite element method is effective for blade analysis. Using Wilson blade optimization method and CATIA and Profili software, the three dimensional model of blade was established. According to the change rate of modal strain energy before and after blade damage, the method can be used as the basis for diagnosing blade damage, and combining modal strain energy change rate with neural network, the method has higher identification rate and can accurately identify blade damage. According to different directions, different positions and different depth of crack damage, the relationship between RMSD and crack damage area S was established by introducing the evaluation index RMSD (mean square value) of leaf health. To some extent, the quantification of blade crack damage is realized. The actuator plays an important role in fault detection, and the choice of the type and excitation frequency of the piezoelectric actuator is particularly important. This paper focuses on the analysis of the geometric size of the actuator and the influence of Poisson's ratio on the resonance frequency. The results show that the finite element method can be used to simulate the damage area on the blade effectively, which can help the wind turbine blade to select the focus area, reduce the labor cost, and improve the detection rate of the fault. Has certain realistic significance. The analysis of external factors in the resonant frequency of piezoelectric actuator, which affects the fault detection, not only provides help for the choice of actuator structure and excitation frequency, but also provides theoretical guidance for the optimal design of piezoelectric actuator.
【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM315

【參考文獻】

相關期刊論文 前10條

1 徐潔;林書玉;;徑向振動環(huán)狀壓電陶瓷復合變壓器的研究[J];西北大學學報(自然科學版);2017年01期

2 司敏R，

本文編號：2145087