考虑强度退化及失效相关性的风电齿轮箱可靠性分析

发布时间：2018-04-05 02:39

本文选题：风电齿轮箱　切入点：可靠性　出处：《兰州理工大学》2014年硕士论文

【摘要】：风电齿轮箱是风力发电设备中的核心部件,具有长寿命和高可靠性等技术要求。但是,由于齿轮传动系统承受的载荷随着风速的变化呈现出高度的不稳定性,导致齿轮箱成为风电机组中失效率最高的部件之一。在这种高度不稳定载荷的长期作用下,一方面,材料内部损伤不断累积,齿轮箱中零件的强度随时间表现出逐渐退化的趋势;另一方面,由于齿轮箱是一个运动和动力耦合的系统,无论是同一零件不同失效模式之间,还是齿轮箱系统中不同零件之间,都普遍存在着失效相关性。因此,本文从强度退化和失效相关这两个角度出发,对风电齿轮箱及其零部件的可靠性进行研究。主要研究结果包括以下三个方面:(1)由于零件强度退化过程中表征退化状态(磨损、裂纹、腐蚀等)的退化数据往往很难直接测量,属于典型的缺失数据。在这种情况下对零件的强度退化过程进行数学建模存在明显的困难。为此,本文用Gamma过程来描述零件强度的随机退化规律,并结合材料的P-S-N曲线对Gamma过程中的特征参数进行估计,建立基于P-S-N曲线的强度退化随机模型。(2)为了对风电齿轮箱中存在的失效相关性进行分析,本文首先利用混合Copula函数来描述齿轮箱中各个零件不同失效模式之间的相关性,实现了零件不同失效模式之间的相关性建模;然后,利用嵌套Copula函数的方法实现了整个齿轮箱系统中各个零件之间的失效相关性建模。(3)为了说明本文提出方法的有效性与合理性,以某2MW风电齿轮箱为研究对象,对本文所提出的理论与方法进行验证和分析。
[Abstract]:Wind power gearbox is the core component of wind power equipment, with long life and high reliability and other technical requirements.However, due to the high instability of the load borne by the gear transmission system with the change of the wind speed, the gearbox becomes one of the components with the highest failure rate in the wind turbine.Under the long-term action of this highly unstable load, on the one hand, the internal damage of the material accumulates and the strength of the parts in the gearbox gradually degenerates over time; on the other hand,Since the gearbox is a kinematic and dynamic coupling system, there is a general failure correlation between different failure modes of the same part and different parts of the gearbox system.Therefore, this paper studies the reliability of wind power gearbox and its parts from the point of view of strength degradation and failure correlation.The main results include the following three aspects: (1) because the degradation data of the degradation state (wear, crack, corrosion, etc.) are often difficult to measure directly in the process of strength degradation of parts, they are typical missing data.In this case, there are obvious difficulties in mathematical modeling of the strength degradation process of parts.In this paper, Gamma process is used to describe the random degradation law of component strength, and the characteristic parameters in Gamma process are estimated with the P-S-N curve of material.In order to analyze the failure correlation in wind power gearbox, the mixed Copula function is used to describe the correlation between different failure modes of each part in the gearbox.The correlation modeling between different failure modes of parts is realized; then,In order to illustrate the validity and rationality of the method proposed in this paper, a certain 2MW wind power gearbox is taken as the research object in order to realize the failure correlation modeling of each part in the whole gearbox system by using nested Copula function.The theory and method proposed in this paper are verified and analyzed.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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