说明：  对电力系统小干扰稳定性进行分析的方法大致可以分为以下几种：数值仿真方法、建立在线性模型基础上的分析方法、小干扰稳定域分析方法、非线性理论分析方法和计及模型不确定性的分析方法。对小干扰稳定性问题可以采用线性模型进行研究，这种线性模型是将描述系统动态行为的微分方程和代数方程在稳态运行点处线性化后得到的。目前，建立在线性模型基础上的电力系统小干扰稳定性分析方法主要有两种：以状态空间模型描述为基础的特征值分析法和以传递函数矩阵为基础的频域分析法。本文采用全部特征值分析法（QR 法）对9节点系统在稳态处进行小干扰稳定分析。
(The analysis methods of power system small disturbance stability can be roughly divided into the following: numerical simulation method, analysis method based on linear model, small disturbance stability region analysis method, nonlinear theoretical analysis method and analysis method considering model uncertainty. A linear model can be used to study the stability of small disturbance. The linear model is obtained by linearizing the differential equation and algebraic equation describing the dynamic behavior of the system at the stable operation point. At present, there are two main methods of power system small disturbance stability analysis based on linear model: eigenvalue analysis based on state space model description and frequency domain analysis based on transfer function matrix. In this paper, the QR method is used to analyze the stability of 9-node system at steady state.)