不同故障下水轮发电机组轴系的振动特性研究

Study on Vibration Characteristics of Shafting of Hydro-generator Set Under Different Faults

水轮发电机组的振动往往由水-机-电耦合因素引起,分析单一故障及多因素耦合故障下的轴系振动对机组稳定运行和厂房结构安全至关重要。采用四阶龙格-库塔法分别求解了不平衡磁拉力、碰摩力、非线性油膜力单独作用或耦合作用下的发电机和水轮机振动特性。结果表明,仅考虑不平衡磁拉力或仅考虑碰摩力时,轴系的运动特性主要表现为周期运动状态和拟周期运动状态;在多因素耦合作用下,轴系的运动特性将会变得更为复杂,表现为以拟周期运动和混沌运动为主,间歇性出现周期运动。研究结果可为水电站的安全、稳定、优化运行提供更多的理论依据。

Hydraulic-mechanical-electrical coupling factors are often responsible for the vibration of hydro-generator sets.The stability of the unit and the safety of the structure of the hydropower plant are greatly dependent on the analysis of shafting vibration under single fault and multi-factor coupling faults.Under the influence of an unbalanced magnetic pull,friction force,and nonlinear oil film force,this paper uses the fourth order Runge-Kutta method to solve the vibration characteristics of the generator and turbine,respectively.In the presence of unbalanced magnetic force or friction force,shafting dynamic characteristics are mainly periodic and quasi-periodic.The dynamics of shafting will become more complex under the multi-factor coupling,which is mainly characterized by quasi-periodic and chaotic behavior,alongside intermittent periodic hehavior.It provides a theoretical basis for the safe,stable,and optimal operation of hydropower plants.