中文摘要：

报告了风力机组机网扭振问题的研究现状，指出了研究并网大型风力机组机网扭振问题的必要性。针对定桨恒频双速异步风力发电机．建立了研究风力发电机和电网之间扭振相互作用的统一机电动态模型：利用有限元分析法对风机叶片进行了建模．将风力机机械部分（包括叶片、低速轴、齿轮箱、高速轴、转子组成的旋转系统）等效为柔性连接的三质量块模型，计算了机械旋转系统的固有频率：对电气部分（包括发电机定子和电网）在dq0坐标系下进行了建模。在电磁暂态仿真软件中了建立了仿真模型．通过在输电线路始端设置三相接地短路故障．激发了风力发电机的机网扭振现象。对扭振曲线进行频域分析，发现了扭振频率与计算得出的机械旋转系统固有频率相吻合．验证了模型的准确性。

英文摘要：

Papers on the torsional vibration of grid-connected wind generator are reviewed and its necessity is pointed out. The unified electromechanical models of grid-connected stalled wind generator are established for torsional vibration study. The finite element analysis is employed to model the blades and the mechanically rotating system,including the blades,low speed shaft,gear box,high speed shaft and generator rotor,is modeled as three softly-connected masses to calculate its inherent frequency. The electrical part, including generator stator and grid,is modeled in dqO coordinates. The simulation model is built with the electromagnetic transient simulation software and the torsional vibration is excited by setting a three-phase grounding fault at the beginning end of transmission line. The simulated torsional vibration curves are analyzed in frequency domain,which shows the vibration frequency is consistent with the calculated inherent frequency and proves the correctness of the established models.