【作者】 王峥；

【导师】 顾桂梅；

【作者基本信息】 兰州交通大学 ， 系统分析与集成， 2015， 硕士

【摘要】 随着可再生能源的开发与应用,风能以其资源丰富、分布广泛以及对环境影响小等特点,已成为世界各国的主要能源之一,风电技术也日趋成熟。叶片作为风电机组的重要组成部分,在恶劣的自然环境中很容易发生损伤,且由于各种因素的影响,不能及时有效地对叶片的损伤进行识别。叶片损坏将对风电场造成严重的经济损失,也对风力发电机的安全运行构成了很大的威胁。因此,研究叶片在常见损伤类型下的损伤诊断方法具有重要意义。本文在分析叶片常用损伤识别方法的基础上,对基于振动检测技术以及计算智能技术等关键技术应用于叶片的结构损伤识别进行了深入的研究。首先,分析介绍了叶片基本结构、常见损伤类型以及现有叶片损伤识别的常用方法,为后续叶片有限元模型的建立以及损伤诊断方法的合理选取进行必要的理论准备。其次,根据叶片在实际环境中的运行特点,将其转换为与实际结构相近的悬臂梁模型,并以2MW风机叶片为研究对象,在ANSYS中创建其有限元模型,计算叶片损伤前后的模态参数值,并采用基于振动特性的损伤识别方法对叶片的损伤进行定位。然后,将叶片的损伤识别问题转化为目标函数优化的数学问题,分别采用常用的遗传算法和果蝇算法对叶片的损伤进行识别,并针对果蝇算法在识别精度方面的不足,对算法进行了改进。通过叶片单损伤和多损伤的数值仿真结果表明,改进后的方法对叶片不同损伤工况的识别精度都有明显提高。最后,搭建叶片振动检测系统的实验平台,通过开裂纹的方式对叶片的裂纹损伤进行模拟,并采用运行模态分析技术对小型叶片损伤前后的模态参数进行求取,然后采用上述方法对叶片的损伤进行识别,从而证明该方法用于叶片损伤识别的有效性。更多还原

【Abstract】 With the exploitation and utilization of renewable energy, wind energy has become one of the primary energy of the world because of its abundant reserves, extensive distribution and little impact on the environment, and wind power technology is also increasingly developed.As the key components of the wind turbine, wind turbine blades is easy to damage in the harsh natural environment, and due to the influence of various factors, the damage of blade can’t be identified timely and effectively. Blade damage will cause serious economic losses on wind farm, and it also has a very important influence on the safe operation of wind turbines.So the research on damage identification method of wind turbine blade under common damage types is very important. Based on the analysis of common damage identification method, the application of vibration testing technology and computational intelligence technology to structure damage identification of wind turbine blade is paid more attention in the thesis.Firstly, the basic structure of the blade, common damage types and the common damage identification method of blade are introduced, which provide the theoretical basis to establish the finite element model of the blade, and to choose the damage identification methods.Secondly, based on the operation characteristics of blade in the real environment, the blade is treated as a cantilever beam which has the same structure as blade. Then take a 2MW wind turbine blade as research object, which finite element model is built based on ANSYS,so the blade modal parameters can be calculated before and after damage, and damage identification method based on vibration characteristic is adopted to identify the damage position of the blade.Then, the damage identification problem of blade can be converted to a mathematical problems, which is about objective function optimization. The common genetic algorithm and fruit flies algorithm is adopted respectively to identify the damage of the wind turbine blade,and the fruit flies algorithm is improved for its lack on identification accuracy. Through the numerical simulation results of single damage and multiple damage of blade, we can find that the improved method has an obvious improvement of the recognition precision under different damage condition.Finally, a laboratory bench for vibration testing system of blade is set up. Through the method of manufacturing crack to simulate the crack damage of blade, the modal analysis technology is adopted to calculate the modal parameters before and after the damage of blade,then the method above can be used to identify the damage of the blade, which can prove the effectiveness of the method for the identification of blade damage.更多还原