大型风力机系统运行模态分析研究

针对大型风力机在风轮静止、变速转动下振动模态及变化特点，研究弹性变形、惯性及陀螺效应引起的系统各阶模态变化及对系统气弹稳定性影响。通过研究现有线性特征值分析方法，考虑大型风力机非线性特性及风轮转动所致系统时变特性，基于多体系统动力学理论及混合多体系统HMBS (Hybrid Multi-body Systems)建模方法，结合动力学分析软件ADAMS，分析静止状态整机系统线性特征值问题；考虑构件弹性变形及风轮旋转，用刚性积分方法对系统非线性控制方程进行数值求解，通过傅里叶谱分析方法实现风轮旋转下系统运转模态识别，并讨论、分析系统前十阶模态变化及影响因素。研究结果可作为风力机系统气弹稳定性判据，为避免共振、提高系统运行效率等提供有效的解决手段及分析方法。

Operational modal analysis of a large wind turbine

This paper aims to research the vibration modes and its variation characteristics of large wind turbine under static status and various rotational speeds. The variation of each mode caused by elastic deformation, inertia and gyroscopic effect and its effects on aeroelastic stability of wind turbine system were studied. Taking the large wind turbine system’s non-linear characteristic and time-varying characteristic caused by the rotational wind rotor into account, the linear eigenvalue problems of wind turbine were analyzed first via dynamics software ADAMS, based on dynamics theory of multi-body system and modeling methodology of Hybrid Multi-body system (HMBS). Next, stiff integral method was employed to numerically solve the non-linear control equations of system considering the elastic deformation of flexible components and the rotation of wind rotor. The operational modal identification was performed through Fourier spectral analysis method. The variation characteristics of the system’s first ten modes and their influencing factors were discussed and analyzed in detail. The research results can be used as aeroelastic stability criteria which offer effective solution and analysis method for avoiding resonance and improving operating efficiency of wind turbine system.