中文摘要：

指出了研究并网大型风力机组机网扭振问题的必要性,为研究风电机组的机网扭振问题,针对失速型异步风力发电机,建立了研究其风力发电机和电网之间扭振相互作用的统一动态模型。采用有限元方法分析了实际的叶片结构,将风力发电机叶片、低速轴、齿轮箱、高速轴、转子组成的旋转系统等效为三质量块-弹簧模型,同时建立了发电机定子和电网在d-q坐标系下的模型,实现了机网接口。仿真分析得到了风力发电机的旋转系统在电网三相故障激励下叶片的扭振曲线,其扭振频率与风机旋转系统的理论固有频率相同,且故障切除以后扭振现象并未衰减;为进一步研究抑制机网扭振的方法提供了理论基础。

英文摘要：

The importance of studying on the torsional vibration of grid-connected wind turbine is discussed.The general dynamic model of grid-connected stalled wind turbine as well as the grid was established in order to research on the interaction between the wind turbine and the grid.The finite element method was applied to analyze the blade structure because blades are fairly dominant in the rotating system of a wind turbine.A three-mass model was used to describe the rotating system includeing blades,low speed shaft,gear box,high speed shaft and the rotor of the generator,while via the d-q coordinates transformation the models of stator and grid were obtained,and it realized the grid-machine interface.The simulation results show that the torsional vibration of the wind turbine rotating system could be excited after three-phase ground fault,It also prove the correctness of the dynamic model and provided the theory foundation for the further study.