计及双馈风机(DFIG)调频特性，建立适用于暂态功角稳定性分析的DFIG等值阻抗模型。在含DFIG的扩展双机系统中，将其等值为含DFIG的扩展单机无穷大系统，基于等面积定则推导出极限切除角关于风电比例和调频控制中下垂系数的表达式，进而理论分析系统极限切除角随DFIG的风电比例和下垂系数的变化趋势，并结合功角特性曲线揭示其变化的内在机理。充分考虑DFIG低电压穿越特性和调频控制特性，在PSD-BPA中对DFIG进行详细建模，搭建了含详细风电模型的扩展两机系统和云南电网仿真模型，对理论分析结果进行仿真验证。理论分析与仿真结果均表明,DFIG参与调频对系统暂态功角稳定性具有一定的改善作用。

Taking into account the frequency-modulation characteristics of doubly-fed induction generator(DFIG), the equivalent impedance model of DFIG for transient power angle stability analysis is established. For the extended dualmachine system with DFIG, it is equivalent to an extended single-machine infinite-bus system. Based on the equal-area criterion, the expression of the limit clearing angle about the wind power proportion and the droop coefficient in frequency-modulation control is derived. The change trend of the limit clearing angle of the system with the wind power proportion and droop coefficient of DFIG is analyzed theoretically, and the internal mechanism of the change is revealed in combination with the trend of power-angle characteristics. Considering the low-voltage ride-through characteristics and frequency-modulation control of DFIG, a detailed model of DFIG is built in PSD-BPA. The extended dual-machine system with detailed wind power model and Yunnan power grid simulation model are built to verify the theoretical analysis results. Theoretical analysis and simulation results show that DFIG participating in frequency-modulation can improve the transient power angle stability.