基于复杂扰动的水电机组与厂房振动传导研究

发布时间：2018-03-06 04:39

本文选题：水电站机组与厂房结构　切入点：测试信号积分方法　出处：《大连理工大学》2014年博士论文　论文类型：学位论文

【摘要】：随着电站规模、水头、容量的提高,机组与厂房结构尺寸越来越大,对机组的安全稳定运行要求逐渐提高,水电站的振动稳定性逐渐成为研究、制造、运行的关键课题。近年来,国内外一些高水头、大容量水电站的厂房结构出现了明显的振动问题,甚至发生破坏。这些实际问题的存在,使得厂房结构的振动机理研究更为紧迫。水电站长期处于强噪声工作环境,测量得到的参数伴随的扰动十分复杂,在振源相互耦合、结构强非线性的振动系统中,如何识别振源的成分、振动传递的具体路径,已成为目前水力发电领域的一个热点和难点。本文围绕复杂扰动条件下水电站振动的传导问题展开研究,结合信号分析、随机振动和振动传导等理论,研究了复杂扰动条件下水电站水力振源竖向振动传导路径的分析理论与计算方法,探讨了水电站振动传导的梯度排序问题,提高了随机振动问题中扰动分析的准确性,为振动控制以及振动稳定性分析提供了理论支撑。论文主要研究内容和成果如下： (1)针对时域积分产生漂移以及频域积分累积误差较大的问题,结合水电站振动信号的特征,提出一种适用于水电站振动测试信号的二次积分算法。该算法以EMD分解为基础,利用其自适应滤波特性剔除频域积分所产生的趋势项误差。算例表明,该方法具有较高的计算精度,能够完整保留信号的频域特性,可用于工程实际。 (2)水电站工作运行时,噪声污染严重,使得各参数伴随大量由不同成因组成的扰动因素,单一扰动量不足以完整描述。针对该情况,本文提出采用双扰动形式,特别是同时包含乘性扰动、加性扰动的混合型扰动形式对各参数所含扰动量进行刻画,推导出相应的随机振动分析方法,并通过算例验证了可行性及有效性。 (3)在双扰动的基础上,进一步研究当扰动之间、参数之间的相关性以及同时存在两类相关性的结构随机振动问题,并推导出相应的计算方法。通过算例分析各类相关性对结构的影响,并最终应用于水电站水力振源竖向振动传递路径分析。算例表明,当随机参数较多时,参数之间的相关性不可忽略。 (4)在以往水力振源竖向振动分析模型的基础上引入顶盖子系统,建立了一个更为完善的、可用于振动传导分析的水电站水力振源竖向振动简化模型。在考虑质量、阻尼、刚度参数具有复杂扰动条件下,对竖向振动传递路径进行理论分析和数值计算,在频域内给出各竖向振动传递路径的传递率及其概率特征,并利用功率流方法相互印证。
[Abstract]:With the increase of the scale, head and capacity of the power station, the size of the unit and the structure of the powerhouse are becoming larger and larger, and the requirements for the safe and stable operation of the unit are gradually increased, and the vibration stability of the hydropower station becomes the research and manufacture gradually. In recent years, some high water head and large capacity hydropower plant structures at home and abroad have appeared obvious vibration problems or even destroyed. These practical problems exist. The study of vibration mechanism of powerhouse structure is more urgent. The hydropower station is in the working environment of strong noise for a long time, and the disturbance associated with the measured parameters is very complicated, in the vibration system with the coupling of vibration sources and the strong nonlinear structure, How to identify the components of vibration sources and the specific path of vibration transmission has become a hot and difficult point in the field of hydropower. Based on the theory of signal analysis, random vibration and vibration conduction, this paper focuses on the vibration conduction of hydropower station under complex disturbance conditions. This paper studies the analysis theory and calculation method of vertical vibration conduction path of hydraulic vibration source of hydropower station under complex disturbance conditions, discusses the gradient ranking problem of vibration conduction of hydropower station, and improves the accuracy of disturbance analysis in random vibration problem. It provides theoretical support for vibration control and vibration stability analysis. The main research contents and results are as follows:. 1) aiming at the problems of the drift of time domain integral and the large cumulative error of frequency domain integral, a quadratic integral algorithm which is suitable for the vibration test signal of hydropower station is proposed, which is based on EMD decomposition, and combines the characteristics of vibration signal of hydropower station. The trend error caused by the frequency domain integral is eliminated by its adaptive filtering characteristic. The example shows that the method has high calculation accuracy and can completely retain the frequency domain characteristic of the signal, and it can be used in engineering practice. 2) the noise pollution is serious in the operation of the hydropower station, which causes the parameters to be accompanied by a large number of disturbance factors composed of different causes, and the single disturbance quantity is not enough to describe the whole situation. In view of this situation, a double disturbance form is proposed in this paper. In particular, the mixed perturbation form including multiplicative perturbation and additive perturbation is used to characterize the perturbed quantity of each parameter, and the corresponding random vibration analysis method is derived. The feasibility and validity of the method are verified by an example. 3) on the basis of the double disturbances, we further study the random vibration problem of structures with two kinds of correlation and the correlation between the parameters between the disturbances. The corresponding calculation method is deduced. The influence of various correlations on the structure is analyzed by examples, and finally applied to the analysis of vertical vibration transfer path of hydraulic vibration source of hydropower station. The calculation example shows that when the random parameters are more, The correlation between parameters cannot be ignored. On the basis of the previous vertical vibration analysis model of hydraulic vibration source, a more perfect simplified model of vertical vibration of hydraulic vibration source of hydropower station is established by introducing the roof subsystem, which can be used for vibration conduction analysis. Considering the mass and damping, the vertical vibration of hydraulic vibration source of hydropower station is simplified. The vertical vibration transfer paths are theoretically analyzed and numerically calculated under the condition of complex disturbance of stiffness parameters. The transfer rate and probability characteristics of each vertical vibration transfer path are given in the frequency domain, and the power flow method is used to verify each other.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TV312

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