水电站机组-厂房结构过渡过程动力系统建模及其瞬态振动响应机制研究

The large-scale construction and intricate operation condition of hydropower station in China, make the vibration problems of unit-plant structure during transient process become increasingly prominent. Although the in-depth understandings have been obtained by huge amount of scientific scholars in the field of vibration characteristics for this structure under the stable working condition, the corresponding theoretical research under transient working condition now is seriously lagging behind the actual engineering practice, which restricts the further pursuit to improve the transient vibration of unit-plant structure in terms of reasonable control mode and technical measure. In this project, the relationship between flow, rotating speed and excitation current from hydraulic, mechanical as well as electrical operating parameters, and corresponding dynamic loads exerted on structures, is used to build the bridge connecting transient process and unit-plant structure vibration. Through establishing the dynamic model of unit-plant structure in the transient process, the numerical calculation method is adopted to investigate the dynamic characteristics of this structure in the transient of load rejection and sudden load increasing (decreasing), for purpose of clarifying the transient vibration mechanism of the structure under the mentioned-above non-stable operating conditions. Furthermore, the relevant results will be compared with field test ones to verify the accuracy and reliability of numerical analysis. The work of this project will provide feasible and reliable analysis model, as well as the study method for dynamic response investigation, stability research and diagnosis analysis of mechanical and civil structures such as hydraulic generating set and hydropower plant.

我国水电站建设的大型化和运行条件复杂化使得机组-厂房结构在过渡工况下的振动问题日益突出。虽然国内外学者对该结构在稳态工况下的振动特性已有较为深入的了解，然而，其在过渡工况下的理论研究严重滞后于工程实践，制约了机组-厂房结构进一步寻求改善其瞬态振动的合理控制方式及技术措施。本项目以流量、转速、励磁电流等水、机、电运行参数和水力、机械、电磁等结构动荷载之间的联系搭建过渡过程与机组-厂房结构振动的桥梁，通过构建机组-厂房结构在过渡工况下的动力学模型，采用数值计算方法对其在甩全部负荷及突增（突减）负荷过渡工况下的动态特性进行研究，明确该结构在上述过渡工况下的瞬态振动响应机制，并与现场实测结果进行对比，验证数值分析的精度及可靠性。项目研究成果将为水电机组及厂房等机械和土建结构在过渡工况下的动力响应分析、稳定性研究以及故障诊断分析提供合理可靠的分析模型与研究方法。

我国水电站建设的大型化和运行条件复杂化使得机组-厂房结构在过渡工况下的振动问题日益突出。虽然国内外学者对该结构在稳态工况下的振动特性已有较为深入的了解，然而，其在过渡工况下的理论研究严重滞后于工程实践，制约了机组-厂房结构进一步寻求改善其瞬态振动的合理控制方式及技术措施。本项目以流量、转速、励磁电流等水、机、电运行参数和水力、机械、电磁等结构动荷载之间的联系搭建了过渡过程与机组-厂房结构振动的桥梁，通过构建机组-厂房结构在过渡工况下的动力学模型，采用数值计算方法对其在甩全部负荷及突增负荷过渡工况下的动态特性进行了研究。通过与现场实测结果进行对比，证明了项目所提出模型可以较为准确地模拟计算水电站系统的开机、增负荷工况运行过程，并能够较好反映水电站运行时的各种非线性动力特性，从而明确了水-机-电-结构耦联系统在过渡工况下的瞬态振动响应机制。针对水电站系统较为复杂的特点，该模型的构建可对电站发电系统进行全面的数值模拟以评价和预测其运行安全性和结构可靠性。项目研究成果将为水电机组及厂房等机械和土建结构在过渡工况下的动力响应分析、稳定性研究以及故障诊断分析提供合理可靠的分析模型与研究方法。