Interaction between wind farms and AC systems can cause oscillatory instabilities across a wide frequency band. Owing to the high-order nature of integrated wind power system, it is almost impossible to determine the system stability directly with the criterion based on the zeroes of the determinant of the impedance matrix. To address this issue, a stability analysis method of zeros identification based on frequency response characteristics of the determinant of the impedance matrix is proposed in this paper. It divides the concerned frequency band into several sub-bands. In each sub-band, a unified reduced-order frequency response model is established, which retains the dominant oscillation mode and a simplified equivalent term of other modes. Therefore, the unknown parameters are significantly reduced, and then the remaining parameters can be easily identified by the fitting algorithm. Finally, zeros of the reduced-order frequency response model in each sub-band can be solved to analyze the system stability. Practical procedure of the proposed method for application in the high order system is proposed. Both the eigenvalue analysis and time-domain simulations performed in three representative systems have validated effectiveness and accuracy of the proposed procedure.

中文翻译：

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基于子带降阶阻抗模型零点辨识的综合风电系统稳定性分析

风电场和交流系统之间的相互作用会导致整个频段的振荡不稳定性。由于综合风电系统的高阶性，直接用基于阻抗矩阵行列式零点的判据来判断系统稳定性几乎是不可能的。针对这一问题，本文提出了一种基于阻抗矩阵行列式频率响应特性的零点识别稳定性分析方法。它将相关频段划分为几个子频段。在每个子带中，建立统一的降阶频率响应模型，该模型保留了主导振荡模式和其他模式的简化等效项。因此，未知参数显着减少，然后剩下的参数可以很容易地通过拟合算法识别出来。最后，可以求解降阶频率响应模型在每个子带中的零点来分析系统稳定性。提出了在高阶系统中应用所提出方法的实际过程。在三个有代表性的系统中进行的特征值分析和时域模拟都验证了所提出程序的有效性和准确性。