主导低频振荡模式二阶非线性相关作用的研究

在大干扰下系统稳定性的研究中，由于特征向量线性变换的引入，使得计算一些衡量模式间非线性相关作用大小的系数不确定，且系统关键参数的变化将造成主导低频振荡模式和相关模式间非线性相关作用的变化，进而导致系统动态特性和稳定性也随之变化。针对此问题，该文应用向量场正则形理论，提出了一种识别大干扰下系统关键参数的方法，即通过标幺化处理来鉴别模式间2阶非线性相关作用大小的方法。研究结果验证了文中分析的正确性，为大干扰下主导低频振荡模式与其它模式非线性相关作用的研究找到了解决其物理量不唯一问题的办法。

STUDY ON THE SECOND ORDER NONLINEAR INTERACTION OF THE CRITICAL INERTIAL MODES

On power system large disturbance stability research, when the linear transformation from the eigenvectors is conducted, the variable problem of the coefficients to quantify nonlinear interactions among modes is appeared, the system dynamics performance and stability may be changed in pace with varying of the nonlinear interaction between the critical inertial modes and the participation modes which is resulted from the system parameter modification. Therefore, on the basis of the theory of normal forms of vector fields, an algorithm to identify the system crucial parameters is presented under large disturbance in this paper. That is to identify the second order nonlinear interaction between the critical inertial modes and the participation modes by per unit technology. The results of study show the correctness of theory analysis, and the method is obtained to solve uncertain physical variable problem in the study of the nonlinear interaction between the critical inertial modes and the participation modes under large disturbance.