海上风机结构振动特性分析与动态参数识别研究
发布时间：2018-07-29 07:54
【摘要】：海上风机结构所处的工作环境极为复杂,其运行状态下不仅会受到风、浪、流等多种外部动力荷载的联合影响而诱发风机结构振动,形成环境荷载激励下“机组—塔筒—基础—地基”耦合系统的随机振动问题;同时机组运行还会带来结构内部机械、电磁以及工作设备等原因发生振动从而引起结构出现多谐波激励共同作用下的强迫振动现象。不同特性的外部荷载激励作用在风机结构上会产生不同的体现结构振动的动态特性指标,主要包括结构运行状态下的工作模态、振动振源以及激励荷载等。这些动态指标不仅有利于准确把握风机结构在工作状态下的振动动力特性,而且对海上风机结构在线实时监测与运行安全性评估具有重要的指导意义。因此,本文针对以上有关海上风电各关键问题展开深入的研究,并取得了以下创新性研究成果:(1)基于现场原型观测资料,全面分析海上风机结构在不同运行状态下的振动响应特性及其变化规律。基于某海上风电试验样机原型观测获得的振动位移数据,首先对不同运行工况下海上风机结构振动响应的基本特性进行描述。其次明确风机结构在复杂台风影响期间结构振动与运行因素间的相互关系。最后验证包括环境风速、叶轮转速及机组负荷等多种运行因素间存在的同步性特征,探讨各运行因素对海上风机结构振动的影响机理及相应变化规律,并论证了风机结构在不同工作状态下具有较好的振动安全性。(2)提出一套适用于不同程度谐波激励下海上风机结构的工作模态识别方法,减少了强谐波干扰对识别精度的影响。以现场实测振动位移数据为研究对象,针对海上风机结构在运行状态下受到不同程度谐波激励影响所体现的相异振动特性,结合组合降噪理论提出一套适用于海上风机结构在谐波激励影响下的工作模态识别方法。该方法以特征系统实现法(ERA)与概率密度函数法(PDF)为理论基础,考虑强谐波激励影响并在Hankel矩阵中加入已知的谐波频率干扰成分,达到结构系统特征矩阵中谐波成分与结构固有模态信息完全分离的目的,为海上风机结构在线实时监测提供了有效的方法与途径。此外,再提出一种考虑谐波修正的SSI法(HM-SSI),利用悬臂梁模型说明新方法在识别精度和稳定性上的优越性以及对谐波频率、噪声程度与谐波幅度等干扰的鲁棒性,进而对海上风机多种高转速运行工况下工作模态参数进行识别并通过共振校核方法评估风机结构具有良好的运行安全性。(3)构建了基于谱峭度的振源识别方法,识别明确了海上风机实际运行各工况的振源种类、主振源及其变化规律。针对工作状态下诱发风机结构振动的振源类型及振源机理尚不明确的问题,开展海上风机结构振源识别及其随运行因素变化特性与规律的研究。首先引入谱峭度理论以分辨结构特定频率振动所体现随机或谐波特性,讨论风机结构在运行状态下响应中出现的主要频分信息及结构振动可能振源的形成机理,识别确定引起海上风机结构振动的主要振源类型与相应频域信息。其次深入研究风机结构不同位置的振源分布规律及能量变化特征,明确诱发结构振动各主要振源及其对应能量随运行因素变化的规律,说明各主要振源振动与整体振动幅度间的变化影响关系。最后精细划分谐波激励振源中关于转频(1P)与倍频(主要为3P)部分的能量,论证了转频频率(1P)在风机结构共振校核中的重要性。(4)提出了海上风机结构动力荷载参数的定量优化识别方法,基于实测振动响应全面分析风电结构静、动荷载的影响因素和变化规律。针对在海上风机结构所受到的环境荷载无法具体通过实测方法获得的工程难题,一方面,基于原型观测的动态应变数据给出风机结构筒顶等效静态荷载的理论求解方法,定性地研究不同运行工况下结构整体荷载的变化规律及安全性。另一方面,以停机工况下风机结构为研究对象,综合考虑结构的普遍受力机理构建“海上风机结构动力荷载参数模型”,提出建立了“海上风机结构动力荷载参数的定量优化识别程序系统”。充分利用不同工况下实测结构多点振动响应数据,基于粒子群优化算法(PSO)循环调用风机结构等效数值模型,以寻优思想反馈分析并归纳关键动力荷载参数,对适用于实际海上风电工程的定常阻力与非定常升力系数随环境因素变化的动态规律进行研究。同时,通过对停机状态下动力荷载参数的优化识别,探究了海上风机结构实际工况下所受环境激励特性及荷载模拟中关键参数的选取范围与标准。
[Abstract]:The working environment of the offshore fan structure is very complex, and its running state is not only affected by the combined influence of wind, wave and flow and other external dynamic loads, which induces the vibration of the fan structure, and forms the random vibration problem of the "unit tower foundation foundation" coupling system under the environment load, and the operation of the unit will bring the knot at the same time. The vibration of the internal mechanical, electromagnetic, and working equipment causes the forced vibration of the structure under the joint action of multi harmonic excitation. The external load excitation of different characteristics will produce different dynamic characteristics of the structural vibration on the fan structure, mainly including the working mode of the structure operation state. These dynamic indexes are not only helpful to accurately grasp the vibration dynamic characteristics of the fan structure in the working state, but also have important guiding significance for the on-line real-time monitoring and operation safety assessment of the offshore fan structure. The following innovative research results are obtained as follows: (1) based on the field prototype observation data, the vibration response characteristics and the change rules of the offshore fan structure in different operating conditions are comprehensively analyzed. The data of the vibration displacement based on the prototype observation of a marine wind power test prototype, first of all, the offshore wind turbine junction under different operating conditions. The basic characteristics of the vibration response are described. Secondly, the relationship between the structure vibration and the operating factors of the structure during the complex typhoon is clarifies. Finally, the synchronization characteristics of various operating factors including the ambient wind speed, the impeller speed and the unit load are verified, and the vibration of the offshore fan structure is explored by the various operating factors. The influence mechanism and the corresponding change law, and demonstrate that the fan structure has better vibration safety under different working conditions. (2) a set of working mode identification method is put forward for the structure of the offshore fan under different harmonic excitation, which reduces the influence of the strong harmonic interference on the recognition precision. In view of the different vibration characteristics of the structure of the offshore fan under the influence of harmonic excitation under different degree of operation, a set of working modal identification method for the structure of the offshore fan under the influence of harmonic excitation is proposed in combination with the theory of combined noise reduction. The method is based on the ERA and the probability density function method (PD F) for the theoretical basis, considering the influence of strong harmonic excitation and adding the known harmonic frequency interference components in the Hankel matrix, the purpose of completely separating the harmonic components from the inherent modal information in the structural system characteristic matrix is to provide an effective method and way for the on-line real-time monitoring of the offshore fan structure. In addition, a test is put forward. The SSI method (HM-SSI), considering the harmonic correction, is used to illustrate the superiority of the new method in the recognition accuracy and stability, the robustness to the harmonic frequency, the noise degree and the amplitude of the harmonic, and then to identify the working modal parameters of the sea fan under various high rotational speed operating conditions and evaluate the wind through resonance checking. The structure of the machine has good operational safety. (3) a method of vibration source identification based on spectral kurtosis is constructed to identify the types of vibration sources, the main source and the changing rules of the actual operating conditions of the offshore fan. The study of the identification of the vibration source and its characteristics and laws with the operating factors. First, the spectral kurtosis theory is introduced to distinguish the random or harmonic characteristics of the structure specific frequency vibration. The main frequency information in the response of the fan structure and the formation mechanism of the possible vibrational source of the structural vibration are discussed, and the identification and determination of the sea are made. The main vibration source type and the corresponding frequency domain information of the fan structure vibration. Secondly, the distribution law of the vibration source and the characteristics of the energy change in the different position of the fan structure are deeply studied, and the rules of the main vibration sources and their corresponding energy changes with the operating factors are clearly induced, and the changes between the vibration of the main vibratory sources and the whole vibration amplitude are illustrated. In the end, the importance of frequency frequency (1P) in the resonance check of the fan structure is demonstrated by fine division of the energy of 1P and frequency doubling (mainly 3P). (4) a quantitative optimization method for the dynamic load parameters of the offshore fan structure is proposed, and the static analysis of wind power structure based on the measured vibration response is given. The influence factor and the change law of the dynamic load. On the one hand, based on the dynamic strain data of the prototype observation, the theoretical solution method of the equivalent static load of the fan structure is given on the one hand, and the structure under different operating conditions is qualitatively studied. On the other hand, on the other hand, taking the wind turbine structure as the research object, considering the universal stress mechanism of the structure, the dynamic load parameter model of the offshore fan structure is constructed, and a quantitative optimization identification program system for the dynamic load parameters of the offshore fan structure is proposed. In the same working condition, the multi point vibration response data of the structure are measured. Based on the particle swarm optimization (PSO) cycle, the equivalent numerical model of the fan structure is called. In order to find the optimal thought feedback analysis and induce the key dynamic load parameters, the dynamic law of the constant resistance and the unsteady lift coefficient with the environmental factors is applied to the actual offshore wind power engineering. At the same time, the selection range and standard of the key parameters in the actual working conditions of the offshore wind turbine and the key parameters in the load simulation are explored through the optimization identification of the dynamic load parameters under the downtime.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU317
，
本文编号：2152020
[Abstract]:The working environment of the offshore fan structure is very complex, and its running state is not only affected by the combined influence of wind, wave and flow and other external dynamic loads, which induces the vibration of the fan structure, and forms the random vibration problem of the "unit tower foundation foundation" coupling system under the environment load, and the operation of the unit will bring the knot at the same time. The vibration of the internal mechanical, electromagnetic, and working equipment causes the forced vibration of the structure under the joint action of multi harmonic excitation. The external load excitation of different characteristics will produce different dynamic characteristics of the structural vibration on the fan structure, mainly including the working mode of the structure operation state. These dynamic indexes are not only helpful to accurately grasp the vibration dynamic characteristics of the fan structure in the working state, but also have important guiding significance for the on-line real-time monitoring and operation safety assessment of the offshore fan structure. The following innovative research results are obtained as follows: (1) based on the field prototype observation data, the vibration response characteristics and the change rules of the offshore fan structure in different operating conditions are comprehensively analyzed. The data of the vibration displacement based on the prototype observation of a marine wind power test prototype, first of all, the offshore wind turbine junction under different operating conditions. The basic characteristics of the vibration response are described. Secondly, the relationship between the structure vibration and the operating factors of the structure during the complex typhoon is clarifies. Finally, the synchronization characteristics of various operating factors including the ambient wind speed, the impeller speed and the unit load are verified, and the vibration of the offshore fan structure is explored by the various operating factors. The influence mechanism and the corresponding change law, and demonstrate that the fan structure has better vibration safety under different working conditions. (2) a set of working mode identification method is put forward for the structure of the offshore fan under different harmonic excitation, which reduces the influence of the strong harmonic interference on the recognition precision. In view of the different vibration characteristics of the structure of the offshore fan under the influence of harmonic excitation under different degree of operation, a set of working modal identification method for the structure of the offshore fan under the influence of harmonic excitation is proposed in combination with the theory of combined noise reduction. The method is based on the ERA and the probability density function method (PD F) for the theoretical basis, considering the influence of strong harmonic excitation and adding the known harmonic frequency interference components in the Hankel matrix, the purpose of completely separating the harmonic components from the inherent modal information in the structural system characteristic matrix is to provide an effective method and way for the on-line real-time monitoring of the offshore fan structure. In addition, a test is put forward. The SSI method (HM-SSI), considering the harmonic correction, is used to illustrate the superiority of the new method in the recognition accuracy and stability, the robustness to the harmonic frequency, the noise degree and the amplitude of the harmonic, and then to identify the working modal parameters of the sea fan under various high rotational speed operating conditions and evaluate the wind through resonance checking. The structure of the machine has good operational safety. (3) a method of vibration source identification based on spectral kurtosis is constructed to identify the types of vibration sources, the main source and the changing rules of the actual operating conditions of the offshore fan. The study of the identification of the vibration source and its characteristics and laws with the operating factors. First, the spectral kurtosis theory is introduced to distinguish the random or harmonic characteristics of the structure specific frequency vibration. The main frequency information in the response of the fan structure and the formation mechanism of the possible vibrational source of the structural vibration are discussed, and the identification and determination of the sea are made. The main vibration source type and the corresponding frequency domain information of the fan structure vibration. Secondly, the distribution law of the vibration source and the characteristics of the energy change in the different position of the fan structure are deeply studied, and the rules of the main vibration sources and their corresponding energy changes with the operating factors are clearly induced, and the changes between the vibration of the main vibratory sources and the whole vibration amplitude are illustrated. In the end, the importance of frequency frequency (1P) in the resonance check of the fan structure is demonstrated by fine division of the energy of 1P and frequency doubling (mainly 3P). (4) a quantitative optimization method for the dynamic load parameters of the offshore fan structure is proposed, and the static analysis of wind power structure based on the measured vibration response is given. The influence factor and the change law of the dynamic load. On the one hand, based on the dynamic strain data of the prototype observation, the theoretical solution method of the equivalent static load of the fan structure is given on the one hand, and the structure under different operating conditions is qualitatively studied. On the other hand, on the other hand, taking the wind turbine structure as the research object, considering the universal stress mechanism of the structure, the dynamic load parameter model of the offshore fan structure is constructed, and a quantitative optimization identification program system for the dynamic load parameters of the offshore fan structure is proposed. In the same working condition, the multi point vibration response data of the structure are measured. Based on the particle swarm optimization (PSO) cycle, the equivalent numerical model of the fan structure is called. In order to find the optimal thought feedback analysis and induce the key dynamic load parameters, the dynamic law of the constant resistance and the unsteady lift coefficient with the environmental factors is applied to the actual offshore wind power engineering. At the same time, the selection range and standard of the key parameters in the actual working conditions of the offshore wind turbine and the key parameters in the load simulation are explored through the optimization identification of the dynamic load parameters under the downtime.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU317
，
本文编号：2152020
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