内外激励下风电齿轮传动系统的非线性动力学特性

Nonlinear dynamic features of wind turbine's gear sytems subjected to internal and external excitations

风电齿轮传动系统的动力学研究,对降低齿轮传动系统故障有重要意义。为进一步研究风电齿轮传动系统的非线性动力学特性,采用集中参数模型建立了该系统纯扭转非线性动力学模型。该模型考虑了各齿轮副间时变啮合刚度、综合啮合误差和齿侧间隙非线性因素,以1.5 MW风机额定功率作为传递功率,结合时间历程图、FFT频谱图、相图、Poincaré截面图、分岔图及最大Lyapunov指数图,研究了在激励频率变化下和综合啮合误差变化下系统的动力学特性。结果发现,随着激励频率的不断增大,系统会出现单周期运动、拟周期运动和混沌等动力学行为,且混沌区域会发生改变;随着综合啮合误差的增加,系统由拟周期运动演化为混沌,最终又突变为拟单周期运动,且通过改变综合啮合误差,观察激励频率变化下系统的影响,发现综合啮合误差的减小能够明显的弱化混沌运动。

Studying dynamic features of wind turbine gear systems is of great significance to reduce faults of a system.For further investigating a wind turbine’s gear transmission system nonlinear dynamic characteristics,the lunped mass method was chosen,a torsional nonlinear dynamic model of the gear system was established considering nonlinear factors,such as,gear pairs’time-varying mesh stiffness,gear mesh error and backlash and taking1.5MW wind turbine rated power as the transmission power.The dynamic characteristics of the system were analyzed by using time history figures,FFT frequency spectrum diagrams,phase trajectories,Poincarésections,bifurcation diagram and largest Lyapunov exponent diagram under variations of excitation frequency and gear mesh error.Results showed that with increase in excitation frequency,there are single periodic motion,quasi periodic one and chaos to appear in the system,the chaotic region also changes;with increase in mesh error,the motion of the system changes from quasi periodic one into chaotic one,and finally it becomes a quasi-single periodic motion;reducing mesh error weakens significantly the chaotic motion.