Abstract Impedance-based method is an effective method to analyze the system stability. Based on the impedance stability theory, an improved virtual inductance control method considering PLL dynamic is presented for the stability of doubly-fed induction generator (DFIG) under weak grid condition. Firstly, equivalent input admittance model of the DFIG system including all its controller is developed in the synchronous reference (d-q) frame. Secondly, the generalized Nyquist criterion (GNC) proves that the stability of the DFIG system can be improved by increasing the rotor inductance. Then, a virtual inductance term is introduced into the RSC current controller to emulate additional inductance in the rotor. However, the virtual inductance method may be ineffectual due to the influence of the PLL dynamic under weak grid condition. Therefore, an improved virtual inductance control method considering the PLL dynamic is implemented to improve the stability of the DFIG system under weak grid condition, and the simulation is used to verify the effectiveness of the improved virtual inductance control strategy.

中文翻译：

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基于双馈电机阻抗建模的弱电网下考虑锁相环动态的改进虚拟电感控制方法

摘要 基于阻抗的方法是分析系统稳定性的有效方法。基于阻抗稳定性理论，针对弱电网条件下双馈感应发电机(DFIG)的稳定性，提出了一种考虑锁相环动态的改进虚拟电感控制方法。首先，在同步参考（dq）坐标系中建立了包括所有控制器在内的双馈电机系统的等效输入导纳模型。其次，广义奈奎斯特判据（GNC）证明了通过增加转子电感可以提高双馈电机系统的稳定性。然后，将虚拟电感项引入 RSC 电流控制器以模拟转子中的附加电感。然而，由于弱电网条件下锁相环动态的影响，虚拟电感方法可能无效。所以，