基于仿真模型的水电机组振动特性分析

Vibration characteristics analysis for hydro-turbine generator units based on numerical simulations

振动是影响水电机组安全、稳定运行的重要因素之一,振动特性的研究有助于对机组振动现象的理解和振动故障的诊断。为了研究水电机组的振动特性,建立了机组径向振动转子动力学模型。采用有限元方法建立轴系本体的动力学方程,使得转子模型能够反映真实机组的动力特性。考虑到当前计算能力的限制,边界条件及外部激励的计算采用了简单实用的分析方法。为了更好的与实际监测数据进行对比,仿真模型中考虑了运行工况参数的影响。结合仿真验证的现场实测数据分析很好地解释了原始数据分析中体现出的机组振动特性。而且,基于仿真模型的振动特性分析可以突破实际机组运行条件的限制,更全面的揭示机组的振动特性。

Vibration is a key factor to safe and steady operation of hydro-turbine generator units, and its analysis helps our understanding of this phenomenon and the diagnosis of vibration faults. In this study, a rotor dynamic model of radial vibration was developed to examine the vibration characteristics of hydro units, and a finite element method （FEM） was adopted for more detailed analysis on the dynamic responses of this rotor system. Simple and practical analysis methods were used for calculation of boundary conditions and excitation forces to overcome the CPU cost limit. This model considers different operation conditions to compare with field data, and it was validated with the field data of vibration characteristics. It is shown that the method based on numerical simulations can provide a comprehensive vibration analysis of hydro units, including the operation conditions that cannot be realized in actual cases.