风力发电机组偏航系统颤振分析

CHATTER CHARACTERISTICS OF YAWING SYSTEM IN WIND TURBINE

以风力发电机组偏航系统为对象,研究含干摩擦的偏航系统颤振问题。建立偏航系统的扭转振动动力学模型,采用Stribeck摩擦模型,根据摩擦片实验数据,拟合得到摩擦系数函数。根据风力发电机组的实际结构与工作参数,利用Runge-Kutta-Fehlberg(RK45)法进行数值分析得到偏航系统的动力学振动特性,分析得到的颤振频率与实验测得的系统颤振频率一致,证实了该文中,所建立的理论分析模型与相关分析方法合理。进一步研究风机预紧力与系统振动特性的关系,得到偏航系统时间-位移曲线、时间-速度曲线、相图和频谱图(FFT),结果表明随着预紧力的增加,系统颤振时间增加、颤振加剧。

Nonlinear dynamical chatter induced by dry friction of yawing system in a wind turbine was discussed, and the torsion vibration model was developed. The dry friction function was developed by combining with Stribeck model and experimental friction coefficient data. Subsequently, numerical analyses of dynamic characteristics of chatter of the yawing system were deduced by using the Rnnge-Kutta-Fehlberg method （RK45）. The results show that the chatter frequencies arc consistent with those during the test, and demonstrate the validity of the theoretical model and the relative parameters of the system. The relation between preload which is assembly technological parameter and vibration characteristics is studied, and time-relative displacement curves, time-relative velocity curves, phase portrait and frequency spectrum （FFT） were illustrated meanwhile. The results indicate that the time span and level of chatter vibration aggravate with the increase of preload.