摘要
以水轮发电机组轴系统和基础耦合动力系统为研究对象,提出了带有基础随机外激励的水电机组轴系统的动力学模型。考虑机组的转子不平衡、转轮密封力等非线性作用,建立了该系统的非线性动力学微分方程。应用相应的数值仿真方法,结合轴心轨迹图、Poincaré映射图和分岔图等,研究了不同频率、不同强度和不同谱宽下的基础随机不确定性激励对主轴系统横向振动的影响。结果表明,基础激励频率的改变及强度和谱宽的变化将影响机组轴系统的运行稳定性,导致主轴系统出现多周期运动和混沌运动等复杂的非线性振动现象。研究进一步揭示了水轮发电机组轴系统的一些复杂非线性动力特性的内在机理和影响规律。
This paper presents a new dynamic model of the shaft system of a hydropower generator coupled with external random excitation from its foundation.We establish nonlinear dynamic differential equations for the shaft system,considering the nonlinear effects of rotor unbalance and runner sealing force;numerically simulate the influences of nondeterministic and random foundation excitations on the shaft’s transverse vibrations,using axis orbit diagrams,Poincarémaps and bifurcation diagrams,etc.The results show that the shaft system’s operational stability will be affected by variations in the frequency,intensity and spectrum width of the excitation,leading to its complicated nonlinear vibration behaviors such as period-doubling and chaotic motions.This study helps a deeper understanding of the influence and mechanism of the nonlinear dynamics of hydropower generator shaft systems.
作者
孙万泉
郑泽知
SUN Wanquan;ZHENG Zezhi(School of Renewable Energy,North China Electric Power University,Beijing 102206)
出处
《水力发电学报》
EI
CSCD
北大核心
2020年第3期96-105,共10页
Journal of Hydroelectric Engineering
基金
国家自然科学基金项目(51579100).
关键词
水力机械
水轮发电机组轴系统
基础激励
非线性动力学
随机激励
hydraulic machinery
hydropower generator shaft system
foundation excitation
nonlinear vibration
random excitation
