For the purpose of considering the spatial-temporal characteristics (STC) of large-scale interconnected power system in the modeling, calculation, and analysis of dynamic frequency response (FR), this paper establishes a two-machine equivalent frequency response (TEFR) model and gets its closed-form solution (CFS), which can be used to analytically analysis and fast calculation. In the modeling, the network structure is idealized through simplified matrix of DC power flow and the system is reduced to a typical two-degree-of-freedom vibration system with viscous damping and excitation forces through breaking closed-loop and variable approximation. After that, modal analysis method is managed to obtain TEFR-CFS which represent the dynamic FR of TEFR model as the superposition of system FR and frequency oscillation. And the influence of parameters on frequency oscillation, such as electrical distance, inertial distribution, initial disturbance power distribution coefficient, etc., are analyzed. Furthermore, the analytical expressions of the key characteristics of dynamic FR, such as the initial decline slope, the nadir and the arrival time of nadir, etc., are derived. Numerical simulation proves that STC has significant influence on FR and can be described by TEFR model, TEFR-CFS and the expressions of its key characteristics with accuracy and efficiency.

中文翻译：

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两机等效电力系统的频率响应模型及其闭式解

为了在动态频率响应（FR）的建模，计算和分析中考虑大型互联电力系统的时空特性（STC），建立了两机等效频率响应（TEFR）模型。并获得其封闭格式解决方案（CFS），可用于分析分析和快速计算。在建模中，通过简化的直流潮流矩阵使网络结构理想化，并且通过打破闭环和可变逼近，将系统简化为具有粘性阻尼和激励力的典型两自由度振动系统。之后，运用模态分析方法得到TEFR-CFS，该TEFR-CFS将TEFR模型的动态FR表示为系统FR和频率振荡的叠加。分析了电气距离，惯性分布，初始扰动功率分布系数等参数对频率振荡的影响。此外，推导了动态FR关键特征的解析表达式，如初始下降斜率，最低点和最低点的到达时间等。数值模拟表明，STC对FR有重要影响，可以用TEFR模型，TEFR-CFS及其关键特征的表达式准确，高效地描述。派生。数值模拟表明，STC对FR有重要影响，可以用TEFR模型，TEFR-CFS及其关键特征的表达式准确，高效地描述。派生。数值模拟表明，STC对FR有重要影响，可以用TEFR模型，TEFR-CFS及其关键特征的表达式准确，高效地描述。