水电站机组和厂房耦联系统振动传递特性研究及振动调控

With the development of the hydropower station, the capacity of the hydropower station is continually increasing in China. The problem of the vibration stability becomes more and more important, but the theoretical research and engineering practice are still lag. On the effect of hydro-mechanical-electrical coupling vibration source, it is totally complicated to analyze the vibration transfer between the structure of generator units and powerhouse. It is a hot and difficult point of the research on the vibration transfer with the multi-vibration sources and multi-path about the strong nonlinear structure system. On the basis of the comprehensive simulation about coupling excitation steady and non-steady state, this study mainly concentrate on the components and main paths about units and powerhouse vibration and then disclose the vibration amplification mechanism and main transfer paths in complex excitation with power flow, perturbation theory and so on in the aspect of the energy. The on-site vibration experiment analysis is carried out about some prototype power stations. The testing data is used for signal analysis and inversion recognition, to verify and modify the mathematical theoretical model. Finally, taking for the structure of the powerhouse reinforced concrete an object, the study reach about the units and powerhouse vibration mechanism under the comprehensive excitation sources and vibration transfer mechanism. It provides a reference basis for the vibration isolation, vibration reduction and reinforcement treatment about units and powerhouse structure.

随着水电站的大型化和运行条件的复杂化，机组振动及其诱发的厂房振动稳定性问题日益突出，但理论研究和工程实践仍然滞后。在水力-机械-电磁振源耦合作用下，机组与厂房结构振动的发生和传导机制尤为复杂，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。本课题重点是在综合模拟耦合激励稳态和非稳态特性的基础上，利用功率流、随机摄动理论等方法，从能量的角度分析机组与厂房振动的成分及其主要路径，揭示机组与厂房结构在复杂激励下的振动传导放大机理和主要传导路径；利用原型电站振动试验数据进行信号分析和反演识别，评价验证和修正完善数学理论模型；依靠随机参数结构分析方法分析参数变异性条件下的结构可靠度，最终确立结构振动破坏机制和安全控制主要目标，探讨激励源-传力体-受振体的系统安全调控路径，为机组与厂房结构的隔振、减振及抗振加固处理提供理论依据。

本项目的研究背景是针对水力发电机组和电站厂房结构的振动稳定性而开展的，随着机组容量和水头的不断提高，振动问题日益突出。项目首先针对水电机组轴系统在水力和电磁激励下的非线性稳定性进行了研究，讨论了密封参数对系统稳定性的影响，提出了降低自激振动的措施建议。给予能量有限元理论和功率流理论，研究了通过顶盖的竖向振动传导规律和主副厂房间的振动传递规律，为振动识别和振动调控奠定了基础。在分析水力发电系统水机电结构各子系统振动模型的基础上，探讨建立水机电结构耦联振动分析模型，进而初步计算了过渡过程中水电机组的稳定性趋势。在振动调控方面，重点针对水电站主厂房的振动优化设计，在数值模拟方法和边界条件分析的基础上，研究了材料参数，楼板、立柱、机墩、边墙、围岩约束等对自振特性和振动反应的影响规律，提出了控制厂房振动的有效措施。项目取得了若干学术成果，发表了10余篇学术论文，并在若干大型电站的设计研究中得到应用。