中文摘要：

大规模变速风电机组并网运行引起的风电场安全问题应给予更多关注。以变速风力机整体为研究对象，分析了风力机稳定性与运行状态、控制策略、发电功率以及风速的关系。针对定功率控制过程中出现的失稳现象，建立了定功率控制过程中的小信号模型，通过研究平衡点的稳定性，近似给出了风力机的稳定运行边界。从物理概念分析了平衡点的稳定性，阐述了桨距角和风速变化引起的风力机失稳过程，并提出了风力机稳定性的判别方法。

英文摘要：

After connecting large-scale variable speed wind turbine generators to power grid, much attention should be paid to the safety issues caused by wind turbines. Taking whole variable speed wind turbine as research object, the realtions of wind turbine stability with operation condition, control strategy, generated power and wind speed are analyzed. In allusion to the instability occurred in constant power control process, a small signal model, during constant power control process is built, and by means of researching the stability of equilibrium points the approximate stable operation boundary of wind turbine is given. The stability of equilibrium point is analyzed from physical concept, and the instability process of wind turbine caused by the variation of pitch angle and wind speed is expounded; besides, a practicable method to distinguish the stability of wind turbine is proposed.