基于原型观测的水电机组-厂房结构振动传递路径识别研究

With the development of the hydropower unit, the capacity is continually increasing, and the operation situation become extremely complicated. The problems of the vibration stability become more and more important, but the theoretical research and engineering practice still lag. The occurrence and transmission mechanism of units and powerhouses structural vibration is especially complicated on the base of hydraulic-units-electric coupling. Strongly nonlinear system multi-vibration sources and multi-paths vibration conduction analysis is always the hot and difficult issue. The focus of this paper is that: from the perspective of prototype observation, the method of component identification and vibration source identification is established, with analysis results of dynamic characteristics, EEMD and Blind source separation method. On this basis, the parametric equation is introduced into the conduction function which is tested or numerically obtained. Then, the identification method of vibration transfer path is established. After then, the computation results are modified by use of the stochastic perturbation theory and inversion parameters real values. Finally, the method system of vibration transfer path identification for hydraulic units is established. The method system provides a theoretical support for analysis of vibration source and main transfer path about units and powerhouses vibration. It also reveals vibration conduction amplification mechanism and main transfer path under complex excitation. Furthermore, it provides a theoretical reference for solution of the structural vibration destruction and safety mechanism and for exploration of the systematical safety regulation path of the excitation source, the force transmitting body and the loaded body.

随着水电站机组的巨型化和运行条件的复杂化，机组振动及其诱发的厂房稳定性问题日益突出，但理论研究和工程实践仍然滞后。其中，水-机-电耦合作用下的机组与厂房结构振动的发生与传导机制尤为复杂，强非线性体系的多振源多路径振动传导分析一直是研究的热点和难点。本课题重点是从原型观测的角度，结合动力学分析成果，利用EEMD、盲源分离等方法建立成分识别，进而识别振动来源的方法；在此基础上，测试或数值计算结构的传导函数并引入参数化方程，建立振动传导路径的识别方法；进一步利用随机摄动理论，反演参数真实值，修正计算结果，最终建立适用于水电机组的振动传递路径识别方法体系。方法体系的建立，为分析机组与厂房振动的来源及其主要路径，揭示机组与厂房结构在复杂激励下的振动传导放大机理及主要传导路径提供了技术支持，最终为确立结构振动的破坏机制和安全控制的主要目标，探讨激励源-传力体-受振体的系统安全调控路径提供理论依据。

机组的稳定运行对水电站厂房的上下游经济社会高质量发展具有重要支撑作用，新时期对水电机组厂房的稳定性要求愈发增高，但以原型观测为基础的振动理论分析与工程实践仍然滞后。水电机组受水力-机械-电磁复合振源影响，大体积非线性混凝土结构受力特性、振动传播放大机理十分复杂，有必要进行深入研究。本项目以原型观测为基础，对大体系非线性结构的耦合振源传播与放大机理进行研究。在降噪与预处理的基础上，通过建立改进的时频处理方法、探讨各类阈值的选取原则，最终建立水电机组原型观测信号的源成分分离的数学模型，并对仿真信号、单信号、多信号分别验证了模型的有效性；进一步，基于TPA、混合TPA方法，以实测与仿真计算FRF为核心，构建原型-仿真联立分析模型，通过简支梁结构验证方法的有效性与合理性，最终应用于水电机组振动传递分析；充分考虑结构参数的变异性，探讨随机摄动、二阶摄动、模糊数、区间参数等参数变异分析方法在水电机组中的适用性，最终开展原型-仿真联立分析的水电机组振动传递研究，识别未测振源、明确振动成分的来源、贡献量等。项目探索建立原型-仿真联立分析方法，探讨了水电机组传力体系作用机理及耦合非线性特征，以期为我国水电机组的安全稳定运行、结构设计和优化奠定理论基础，为准确实现振源与结构之间的相互作用提供合原型-数值联立分析方法。